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Technical Information => Electronics => Electronics How-To Guides => Topic started by: halfspec on January 08, 2016, 05:46:29 PM

Title: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on January 08, 2016, 05:46:29 PM
As I step back from producing products for the RX7 community I wanted to turn over my designs and convert my projects into a more open source form. This is one of those projects.

Terms of use Ė I am releasing this information freely and you can do whatever you wish with it. All that I ask is that if you do post this information elsewhere, please provide a link back to this thread. As far as support goes, this thread is it. Please donít PM me with circuit specific or troubleshooting questions. If you have questions, post here and let the very capable community here work it out. If the question canít be answered by the community I will hop in and answer (Iím subscribed to this thread).

93-95 RX7 LSX AC Control

This is a tutorial for constructing and installing an electrical interface system that fully controls your GM compressor as a standalone unit actuated with the stock FD AC button. In its simplest form this is a universal control system that can be adapted to any engine but in this tutorial itís really presented for 93-95 RX7 owners running a LSX engine (LS2, LS3, LS7, LS9, etc). If you have a LS1 fbody PCM and engine, this will also work for you, but you have better & cheaper options available to you here (http://www.norotors.com/index.php?topic=23630.0). This is the exact design I used to create and sell ~75 of these controllers over 3 years and they performed flawlessly with zero returns.

Diagram:

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXACControl_zpsz3tpxq1c.jpg) (http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXACControl_zpsz3tpxq1c.jpg)

This diagram should look somewhat familiar as it takes ideas from Pez and burtoncrís diagrams released years ago. The biggest differences in my design is a diode network designed to allow the PCM and the aftermarket AC controller access to the radiator fan relay(s) without interfering with each other or causing CEL codes. Additionally the design includes a more sophisticated way of handling the AC request signal from the OEM wiring. The AC Signal Intercept adapter. This is a plug-and-play adapter I developed that standardizes the controller wiring but more on that later.

Purpose for a standalone controller

The purpose for this controller is something Iíve been asked more than a few times as most people expect to be able to use the LSX PCM to control the AC similar to what the LS1 PCM is capable of. While the LSX PCM does have the built in I/O and logic to control the AC, there is one problem. The CAN bus.
On post fbody LS1 control systems the analog AC request is accepted by the BCM module then relayed to the PCM via the CAN bus. All RX7 swaps Iíve seen to date have never swapped over the BCM so with a LSX swap and the desire the add AC youíre generally starting with a missing piece.
The correct way to solve this problem would be to design a CAN bus interface that can accept an analog input from an AC request button/switch and outputs that request via a CAN bus code to the PCM. For this to work the CAN bus network to the PCM would have to be rebuilt between the PCM and this new device and then youíd have to turn off a lot of CEL codes since I expect the PCM would report a lot of hardware missing since with an active CAN network it would assume a lot of data is not being reported by the ďBCM.Ē
I tried looking into the route above and may still design a solution down the road, but it is far more complex and undocumented.

Until then, we have another option for AC control. That option is to control the AC system with a standalone controller, which is what this is.

How it works:

This section isnít critical to understand, but Iím going to write it out anyway because if you have problems with the controller, this section is what youíll need to debug it.

RX7 AC Button Signal and the Micro SPST Relay:

This is usually the hardest part for people to grasp. I get questions a lot simply asking how to tap into the RX7ís AC button signal and what is it (12V or Gnd)? The button is overcomplicated in its stock form for such a simple operation. Thatís one of the reasons for the AC Signal Intercept Adapter, as it cuts the complexity in half. With the interceptor installed, hereís how it all works:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/Z68_zpszzsppskz.jpeg) (http://www.halfspec.com/pictures/OpenSource/LS1AC/Z68_zpszzsppskz.jpeg)

In the diagram above the AC switch on the lower right. Notice that it's normally open. See the leg that exits out of 1G. That's the path to ground. How? You'll see it make its way to position 1 of the blower switch. When you switch the blower switch, this is how it gets ground.

Position #1 = Direct patch to ground through the switch
Position #2 = Path to ground through the diode then to through the switch
Position #3 = Path to ground through the diode then through the second resistor then through the switch
Position #4 - Path to ground through the diode then through the second and third resistors then through the switch
My theory on position 3 and 4 and the resistors is that the resistors are very low resistance (like 1-2ohms so they're negligible). The first resistor is a little more substantial therefore the diode path is there to shortcut it in position 2, 3, and 4.

*Note* A fully functioning blower resistor is key to getting a ground signal to the AC switch. If you have a break in the blower resistorís wiring, your AC wonít function in 1 or more positions. This is important because Iíve seen this problem with customers several times over the years and it appears to be getting more and more common as our cars are getting into their mid 20s. If your AC button doesnít actuate the mini SPST relay, my first suggestion is to inspect and verify your blower resistor is working.

When you press the AC switch and your blower switch is in position 1-4 you get a ground out of 1l. This makes its way to the thermoswitch connection G-08.

This is where my proposed adapter picks up the signal. Creating an adapter at G-08 to pickup the signal after the thermoswitch allows us to pick up that ground coming from 1l and use it to activate the Micro SPST relay. Pay special attention to how the AC Signal Intercept Adapter is wired. The violet wire does not pass through to the other side of the adapter. It gets re-routed directly to the micro relay pin 85. You have to do it this way to insure that the factory Fan #1 relay doesnít interfere with the AC request signal.

When the ground signal from the RX7 AC switch activates the Micro SPST relay we short the path between pins 87 and 30 which allows the RPM Window Switchís white output to connect to the AC Pressure Switch.

RPM Window Switch:

The Baker Electronix RWSr Window switch performs 1 step of the control logic to turn on the AC compressor. Its job is simply to determine if the engine RPM is running between 400 and 4800 RPM. If the engine RPM falls out of this range the White output wire is simply Open and if passed through the Micro SPST relay AND the AC Pressure Switch will NOT activate the Mini SPST relay nor provide a Ground at the Fan Relay Output. Only when the engineís RPM range IS between 400-4800 RPM will the white output issue a Ground signal, which if passed through the Micro SPST relay AND the AC Pressure switch WILL activate the Mini SPST relay AND provide a Ground at the Fan Relay Output.

AC Pressure Switch

This is a binary switch with ~13psi of hysteresis and the last step of the control logic. Its primary function is to ONLY pass the Ground command to start the compressor IF the refrigerant pressure is within range. My sensor of choice, the Ryder 1514, levels are as follows: High: Off: 455 On: 341. Low: Off: 28 On: 40. Essentially that means your refrigerant pressure needs to be between 40 and 341 PSI for the AC switch to pass the Ground generated by the RPM window switch and being passed through the Micro SPST relay.

Mini SPST Relay:

Once the RPM window switch generates a Ground and it passes through the Micro SPST relay (actuated by the stock AC Switch), and finally passes the AC switch it arrives at Diode #2 (read below) and the Mini SPST relay contact # 85. The Ground on 85 activates the relay and 12V is sent to actuate the AC Compressor clutch which, if your evaporator, expansion valve, condenser, radiator fans, cabin fan, and air routing within the heater box is working means cold air in yo face! :D

Those Damned Diodes & Fan Control:

Diode 1 is called a flyback diode and itís a type of snubber circuit. Itís actually built into the LSX harness wiring for the compressor if youíve actually pulled one apart. When the voltage to the compressor clutch solenoid is removed the coilís magnetic field collapses which creates a pulse of current flow which therefore creates a negative voltage across the solenoid coil. This short lived reverse voltage is only around in the order of miliseconds, but it can be a couple hundred voltsÖ. Which can pop the mini relay to the left.  The flyback diode (itís just a regular 1N4004 diode) can snub this reverse voltage because when it pops up, it forward biases the diode which sinks everything to ground therefore protecting your relay.

Diode 2 and 3 work together to provide a Ground fan output signal for your fan control relay, but they are arranged in such a way that neither side of the control gets feedback from each other.

Diode 2 will bias when the AC pressure switch passes a Ground, therefore the Fan Relay Output will see Ground. Simultaneously, when Diode 2 is passing a Ground Diode 3 blocks it as a Ground condition on the PCM fan output (that it didnít command) produces a CEL code.

Diode 3 will bias when the PCM ouput passes a Ground (the PCM will output as normal when coolant temp rises above a setpoint) therefore the Fan Relay Output will see Ground. Simultaneously, when Diode 3 is passing a Ground, Diode 2 blocks it as a Ground condition that sees the Mini Relay contact 85 would trigger the relay and activate the AC Compressor Clutch which you wouldnít want as every time your radiator fans come on to cool your coolant levels the AC compressor would come on too).


- Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on January 08, 2016, 05:47:13 PM
Parts List

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXACControlPartsrev2_zps6ezg9kxr.gif) (https://docs.google.com/spreadsheets/d/1o1CnC80zlkcYviQxbB1UCPNS6ob8usgr8rY1Barrxm8/edit?usp=sharing)

*Note* Pay special attention to the orange and yellow highlighting concerning your compressor connector choice. Different engines use different compressors and this will trip you up in more ways than one. The first hurdle relates to the compressor clutch connection. LS3 SS Camaro's use LS1 style connectors so I've included the part numbers to build that connector. CTSV LS3's use a different compressor that has a less standard connector that I haven't been able to figure out how to build from scratch. Luckily you can buy the connector pre-assembled but it's expensive by comparison. If you have a compressor that uses a connector other than these two you'll have to do some digging.

The parts list above is fairly comprehensive. The only thing you may run into is order quantity limitations. Waytekwire is especially picky about low quantity orders which is why I tried to add as many alternatives as possible. Either way, this should give anyone a huge head start on getting one of these high quality controllers built even if the original sources dry up.

Tools of the Trade

As with everything car related, you have to have the right tools to do the job well. That is especially true when you're building something like this. A high quality stripper / crimper will make your life a lot easier, whereas the incorrectly spec'd or insufficient stripper / crimper will make your life a living hell. Believe me. This will be one of the big hurdles DIY folks will face, because we're not just talking pocket change here.

I own the following 3 crimpers:

Pressmaster KRB-0560
(http://www.halfspec.com/pictures/OpenSource/Pressmaster-krb-0560-the-best-crimping-tool_zpsirvktvrl.jpg) (http://www.cycleterminal.com/crimp-tools.html)

S & G Tool Aid 18920
(http://www.halfspec.com/pictures/OpenSource/51ae53xPZhL_zpsny8md1bq.jpg) (http://www.amazon.com/Tool-Aid-18920-Ratcheting-Terminal/dp/B0002STTTI)

Cycle Terminal ECT47
(http://www.halfspec.com/pictures/OpenSource/JAE-090-040-pin-terminal-crimp-tool_zpsbdwls6sg.jpg) (http://www.cycleterminal.com/crimp-tools.html)

I also own the following stripper:

IDEAL 45-092 Stripmaster Wire Stripper
(http://www.halfspec.com/pictures/OpenSource/stripmaster_zps1xdukreq.jpg) (http://www.amazon.com/Ideal-45-292-Stripmaster-Wire-Stripper/dp/B000NBA8GM)

All 4 of the tools above have been worth their weight in gold.

The S & G Tool Aid 18920 was my first ratcheting crimper. It's a good starter crimper and does a lot of things pretty well in the medium of its range. It can handle Delphi 150-480 terminals and it has a great die for crimping barrels & butts.  It's the large and small stuff where it starts to struggle (see my comments on the next two crimpers). I believe a good alternative for this crimper is the Cycle Terminal Eclipse Crimper (http://www.cycleterminal.com/eclipse-tools.html). The only thing I'm not sure about when it comes to the Eclipse crimper is what dies it comes with and what you have to purchase seperately. It makes it sound like it comes with the barrel / bullet die already which would mean you'd probably want the optional "Die for Open Barrel Terminals" or "Die for Small Ring and Splice Terminals " depending on what you're crimping. May be a way to save money over the S&G depending on your application.

The Cycle Terminal ECT47 crimper is for small stuff. I use it almost exclusively for crimping PCM terminals as they're generally made for 20-24AWG wiring and it's just too small for the ratcheting crimpers I have.

The Pressmaster is absolutely amazing. I bought it late in the game as I resisted paying $150+ for a crimper for years. However, after getting it I can't believe how much time and pain it saves me. This is the only crimper I own that can crimp the .312 YMST1418L / YFST1416N terminals. The S&G just doesn't have the leverage to do bigger terminals unless you're related to Hercules and/or can figure out how to use your hydraulic press to help actuate the handles. Seriously, I kiss this one every night before I go to bed.

The ideal stripmaster is one of those tools you can't believe you lived without before you got it. Seriously, it's saved me DAYS in time over the years I've owned it.

Finally, when doing work with small terminals and connection systems that use tangs / locking tabs to secure the terminals, it is VERY important that you have the proper tools to de-pin the connector you're working on. Seriously, you can do a lot of damage and waste a lot of your time trying to use a tool that isn't designed to de-pin. I suggest getting the $13 option from cycle terminal that includes a wide and narrow de-pinning tool:

(http://www.cycleterminal.com/Delphi-equivelant-12094429-Terminal-extractor-removal-tool.jpg) (http://www.cycleterminal.com/crimp-tools.html)

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on January 08, 2016, 05:47:22 PM
Build Instructions

I imagine this is the section most folks are waiting for  :popcorn:

Step 1 - Build the Power Harness

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXpart1_zpshqycwy0o.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/IMG_20160118_134803237_zpseqrnwn68.jpg)

The specifics parts needed are:

6ft Pink 14AWG TXL/GXL wire (main length section)
2in Pink 14AWG TXL/GXL wire (fish-hook / fuse box connection section)
Two lengths of 2 1/2in Pink 18AWG TXL/GXL wire
Mini in-line fuse holder - 46025
Mini 25 A fuse - 46258
.312 Male Terminal = YMST1418L
.312 Female Terminal = YFST1416N
Mini relay terminal = 75280
Micro relay terminal = 75290


(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3692_zpssftoehe9.jpg)
1. On the first end, solder and shrink wrap the 14AWG wire and the fuse holder.
2. On the other end of the fuse holder slice a section exposing bare wire and solder one of the 18AWG wires to it. *Note* Plan and shrinkwrap this connection.
3. At the end of the fuse holder wiring, crimp the Mini relay terminal together with a 2 1/2" Pink 18AWG wire.
4. At the end of the 2 1/2" Pink 18 AWG wire, crimp a micro relay terminal along with the second length of 2 1/2" Pink 18AWG wire

(http://www.halfspec.com/pictures/OpenSource/LSXAC/IMG_20160118_134827272_zpsoo1owril.jpg)
1. On the second end of the 14AWG pink wire, crimp the .312 Male Terminal together with the 2 1/2" pink 14AWG wire.
2. On the other end of the 2 1/2" pink 14AWG wire crimp the female .312 Female Terminal

Step 2 - Build the Pressure Sensor + Fan Control Harness

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXpart2_zpsuyqhvfqt.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3668_zpse0b36ws6.jpg)

The specifics parts needed are:

6ft Purple 18AWG TXL/GXL wire
6ft Gray 18AWG TXL/GXL wire
18in Black 18AWG TXL/GXL wire
18in Orange/Black 18AWG TXL/GXL wire
2in Black 18AWG TXL/GXL wire
2in Pink 14AWG TXL/GXL wire (fish-hook / fuse box connection section)
Two lengths of 2 1/2in Pink 18AWG TXL/GXL wire
Two Pressure Sensor Terminals   829-12084200
Pressure Sensor Connector   829-12052641
Pressure Sensor Lock   829-12052634
AC Pressure Sensor Connector Seal   829-15324818
Two Mini relay terminal = 75280
Two Diodes - 512-1N4004

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3669_zpsbar04vdu.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3671_zpsg5b9s3dh.jpg)

1. Slide the seals onto the gray and purple wires
2. Crimp the terminals on the end of the gray and purple wires.
3. Push the terminals into the pressure sensor connector as well as the seals until the seat and click
4. Install the secondary lock (blue piece)
5. Sleeve if so desired

On the other end of the gray and purple wires:

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3673_zpsg6g9shf9.jpg)

1. Arrange and solder the diodes, black, and orange/black wires together as shown

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3672_zpstobanbtn.jpg)

1. Plan and heatshrink the exposed diode leads then install one more piece of heatshrink to cover the rest of the diodes (not shown)
2. Crimp a Mini relay terminal together with the purple and black wire.
3. Crimp a Mini relay terminal  on the gray wire.

Step 3 - Build the Compressor Clutch harness

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXpart3_zps0kkovqu7.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3657_zpsvecwvezr.jpg)

*Note this tutorial only shows how to build the harness tipped with a connector suitable for a SS LS3 camaro compressor. If you have a CTSV LS3 compressor or other, you'll need a different connector.

The specifics parts needed are:

8ft Black 16AWG TXL/GXL wire
8ft Dark Green 16WG TXL/GXL wire
Two AC Compressor Terminals - 829-12048074
AC Compressor Connector - 829-12162017-B
AC Compressor Connector Lock - 829-12124824-B
Two AC Compressor Connector Seals - 829-15324973
Mini relay terminal -75280
One Diode - 512-1N4004

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3664_zps1v2uulb4.jpg)

1. Slide the seals on the dark green and black wires.
2. Position the diode so the legs slide through each of the seals and meet the tips of the black and green wire. Note the polarity orientation in the pic and schematic! Note 2 - Involving the the diode makes this a tricky crimping operation. I'd recommend dabbing the crimping section of each terminal with solder if possible to insure the diode is bonded to the terminals.
3. Crimp the terminals on the dark green and black wires.

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3666_zpsfkagqecl.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3667_zpsb1gfrjtb.jpg)

1. Align and press in the terminals and seals in the compressor connector.
2. Sleeve if so desired

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3657_zpsvecwvezr.jpg)

1. Crimp the Mini relay terminal on the end of the dark green wire.

Step 4 - Build the AC Signal Intercept Adapter

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXpart4_zpsg2dgtvcq.jpg)

The specifics parts needed are:

3ft Purple 18AWG TXL/GXL wire
3 sections of 2 1/2in gray 16WG TXL/GXL wire
Micro relay terminal -75290
Yazaki CN-A 4 pin Connector Set

(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3577_zpsgorhay3v.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/_GJW3572_zpsdxlbdfxo.jpg)

1. Crimp a Yazaki CN-A male and female terminal on each of the 3 sections of 2 1/2in gray 16WG TXL/GXL wire
2. Crimp the Micro relay terminal on one of the 3ft Purple 18AWG TXL/GXL wire
3. Crimp a Yazaki CN-A female on the other end of the 3ft Purple 18AWG TXL/GXL wire
4. Assemble exactly as shown.

Step 5 - Window Switch Installation + Final Assembly

(http://www.halfspec.com/pictures/OpenSource/LSXAC/assembly_zpscv2ut9en.jpg)


The specifics parts needed are:

Ground Terminal Ring -31004
Mini relay terminal - 75280
Micro relay terminal - 75290

1. Using the main LSX circuit above land all the harnesses you built previously to the mini and micro relay sockets.
2. Install the RPM window switch
    a. Crimp the Mini relay terminal on the end of the RPM switch's green wire and connect it to the micro relay pin 30
    b. Crimp the Micro relay terminal to both the RPM window switch's red wire AND the loose pink end off your Power harness you build earlier. Connect it to the micro relay pin 86
    c. Crimp the Ground Terminal Ring to both the RPM window switch's black wire AND the loose black wire off your Compressor harness you built earlier.
3. Install relays
4. Have a beer or 10.

Closing Notes

1. You may notice that I sometimes say connect to pin 85 in my schematics and I connect to pin 86 in my pictures or vice versa. Polarity doesn't matter with the relays I've specified so the two are 
    interchangeable. As long as a ground is on one side and 12V is on the other side, the relay will activate. Pins 87 and 30 are also interchangeable. I just make use of this fact to simplify wiring.
2. If you want to get into the nitty gritty. I don't crimp my seals correctly in the pictures above. The secondary crimp on the terminals is supposed to be used to crimp the seal AND the wire insulation like this:
(http://www.halfspec.com/pictures/OpenSource/LSXAC/ly6swap621_zpsoed3xdbe.jpg)
As a amateur I just crimped to the wire insulation as having the seals movable have me a little bit of flex for moving things around like the diode on the compressor connector. Still, if seals are involved, and you want to do it right, try and do it like the picture above shows.

- Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on January 08, 2016, 05:47:29 PM
Installation

Ok so youíve got your controller built and it looks a little something like this:

(http://www.halfspec.com/pictures/OpenSource/LSXAC/ls2kitrev23_small_zpssao17dmm.jpg)
(http://www.halfspec.com/pictures/OpenSource/LSXAC/ls2kitrev22_small_zpswgomjbxq.jpg)

Time to install it!

This installation tutorial is divided up into 3 parts. Part 1 covers the RX7 electronics side of the install. Part 2 covers optional connections. Part 3 covers the initial power up and testing.

Part 1 Ė RX7 and chassis wiring

(http://www.halfspec.com/pictures/OpenSource/LSXAC/lsxwiring_zpsimywll7r.jpg)

1.   This controller is made to be mounted in the passenger side kickpanel area, so thatís where it will be easiest to locate everything unless youíve tailored your wiring and deviated from the plans above.
2.   Prepare 1 of the 3 or 4 studs in that area to be used as a ground location. This means to remove any paint down to the bare metal and any dirt away from the base of the stud.
3.   Using the 6mm lock nut included in your kit, bolt the ground terminal to this prepared stud. See the pic below:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/IMG_0196_zpsjdhdl73d.jpg)
Note Ė This stud has NOT been prepared properly. Please make sure the ground terminal makes good contact with bare metal at the base of the stud.

4.   Remove the 25A fuse from the 12V switched wire.
5.   After removing the fuse, route the 12V Switched plug from the passenger side to the driverís kick panel. I find that routing along the firewall and over the transmission tunnel to be the most direct / clean route.
6.   Unplug, unbolt, and unclip the driverís side fuse box. Tip #1 Ė Remove your kick panel and dead pedal. Tip #2 the fuse box has one bolt towards the floor board and one VERY hard to reach clip at the top (See pic below). Please be careful not to break this clip. It is possible to see the clip with some finagling, but it IS difficult and probably one of the more frustrating parts of the job.

(http://www.halfspec.com/pictures/OpenSource/LS1AC/powerbrick_zpsxcpgovjw.jpg)

7.   Flip the fuse box over and look for 3 position black connector with three large wires colored Blue, Black/White, and Black/Yellow.

(http://www.halfspec.com/pictures/OpenSource/LS1AC/IMG_0131_zpsjubatuxf.jpg)

8.   Unplug the black connector and use a small flat head screw driver to de-pin the Black/Yellow wire.

(http://www.halfspec.com/pictures/OpenSource/LS1AC/IMG_0121_zpsmnrufd7e.jpg)

9.   The pin should come out looking like this:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/IMG_0119_zpssnkwi5yf.jpg)

10.   Slide some ľĒ shrink up and over the female terminal above.
11.   Install the Male side of the 12V Switched Plug onto the original Female terminal above, then heat the shrink-wrap over the connection (not shown).
12.   Plug the Female side of the 12V switched Plug into the black connector like this:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/IMG_0123_zpswwootsvs.jpg)

13.   Push the connector into the black connector until it clicks.
14.   Reassemble your fuse box and replace any panels you removed to access it.
15.   From the passenger kick panel, plug the A/C G-08 Signal intercept adapter between the Evaporatorís Dash Wiring and its Thermoswitch:

*Note* G-08ís location has been a subject of confusion for many over the years I sold this controller. Folks canít seem to find the thermoswitch plug G-08. Itís slightly different for Mana and Denso evaporators. Here is the diagramed location:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/expansion_zpsyqoggs6g.jpeg)
The thermoswitch is labeled as '4' in the pictures above and G-08 is the 4 pin electrical connector at the end of its wiring pigtail

Hereís my Denso connector hanging down from its clip (Itíll be clipped up further in the dash via its stock configuration unless someoneís been toying around (like me in this picture))

(http://www.halfspec.com/pictures/OpenSource/LS1AC/thermoswitch1_zpslabhwrzi.jpg)

And finally, hereís a memberís Mana G-08 clipped to the evaporator case as it should be:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/thermoswitchconnectorMANA_zps1b8f2f3a.jpg)

16.     Take the green RPM wire and tap into the RPM signal coming from your PCM and leading to your Tachometer. It is reccomended that this connection be soldered and heatshrinked or crimped and heatshrinked.
17.   From the passenger kick panel, route the compressor control plug to the compressor. The length instructions above are meant to route through the airbag harness grommet and up and over the inside of the fender to right in front of the wheel where it can easily make its way to the compressor. Kind of like the picture above but on the passenger side:

(http://www.halfspec.com/pictures/OpenSource/LS1AC/IMG_1292_zpscn6ady36.jpg)

18.   The method above does require the temporary removal of your fender.
19.   Another method would be to route through the engine harness grommet or drill a new hole and install a new grommet to pass through.
20.   Plug in the compressor control plug.

Optional Connections

1.   This design includes the ability to provide a GROUND to a fan relay coil when the A/C switch is pressed as well as provide a path for PCM control of that fan without interfering with the PCM. The idea being that the fan will provide additional cooling for the condenser when the car has the A/C running in stop and go traffic.
2.   Most fan setups involve the PCM to provide primary control of the fans.
3.   In the setup mentioned in the above step the PCM has two wires that lead to 2 or 3 relays to control high and low speeds.
4.   The PCM grounds the low speed wire to enable low speed operation and also grounds the high speed wire to enable high speed operation.
5.   The way the fan function works in my kit is that it passes commands from the PCM through its wiring, but also has the ability to override these commands and turn the fan on by itself when the A/C button is installed.
6.   To install this feature:
   a.   Severe / Cut the low speed wire connection between the PCM and the Low speed relay.
   b.   Splice the A/C Controllerís Orange with Black strip wire to the wire leading back to the PCM. It is recommended that this connection be soldered and heatshrinked or butt crimped and heatshrinked.
   c.   Splice the A/C Controllerís Black wire to the wire leading out to the low speed fan relay. It is recommended that this connection be soldered and heatshrinked or butt crimped and heatshrinked.


Part 3 Ė Powering up and testing

1.   Plug the 25A fuse into the 12V Switched wireís fuse holder which is near the relays in the passenger kick panel area.
2.   If your system isnít charged and your pressure switch isnít installed, youíll have to jump the pressure switch connector with something line a non-insulated (bare metal) paper clip. The pressure switch used with the LS2/LS3 kit is simply a on off switch and has no polarity. It stays closed when the pressure is right in the system and passes the signal through it. It opens up when the pressure is too low or too high and breaks the signal passing through it.
So, to test without actually having the system charged up and the pressure switch installed, you have to jump the two terminals on the pressure switch connector with something like a paper clip.
3.   Turn your key to the ON position (donít start the car yet).
4.   Check the RPM switch to see that its indicator LED turns solid blue then starts to pulse blue.
5.   Crank your car and verify that the RPM switchís main indicator LED turns slightly purple. This indicates that the switch is accepting the RPM signal from the PCM and adds some red light to the indicator LED which signals that the switch is allowing the AC to be turned on (IE the carís RPM is within a safe range). If you turn off the engine or rev over 4800 rpm you will see the the main LED turn back to solid blue (indicating that the RPMs are too low or too high for the AC compressor to be on).

(http://www.halfspec.com/pictures/OpenSource/LSXAC/ls2kitrev24_small_zps46zm8cmu.jpg)
RPM switch with purple indicator light (car on and idling)

6.    With the car still on, turn on your A/C blower motor, then press the A/C button. You should hear at least one of the relayís click or at least feel it click if you touch it while toggling the A/C switch. You can also check the compressor clutch connector with a voltmeter (if you happen to have one) and youíll see 12v. Additionally, if you have hooked up the fan control wires, you should hear and see your fans turn on. If it does youíre done with the exception that you may need to reconnect your compressor plug and pressure sensor plug if you unplugged them for testing.
If not, check the unitís 25A fuse. If the fuse is intact, check your ground terminal. If needed, clean the contact point again. If that fails, move the ground to another location. If it still doesnít click when pressing the A/C switch please post your questions here and the norotors member will help you.

Otherwise, you should now be able to enjoy the full benefits of having a safely controlled A/C system.

- Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: markfluko on January 08, 2016, 05:49:55 PM
Phew, almost commented right before you made those reservations  :D

Badass work man, real easy to follow.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on January 08, 2016, 05:55:47 PM
Phew, almost commented right before you made those reservations  :D

Badass work man, real easy to follow.

Whoah! Almost ninja'd my ninja edit  :yay:
Glad you're enjoying it so far. Much more to come.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on January 18, 2016, 11:56:07 AM
Done

(http://i.imgur.com/ITlLShQ.gif)

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ccadkins1 on January 31, 2016, 03:18:01 PM
Hello Lane,
I'm apparently the world's biggest idiot, because I'm having trouble getting my AC working.  Hope you can help me!

Some time ago, I bought a line set, dryer, etc. from you, as well as the window switch setup for standalone control.  My swap involves an '04 GTO engine and harness, therefore a lot of the nice ac/fan control isn't present in my PCM.

I have everything installed in the car (lines, dryer, harnesses, etc.).  My GTO PCM controls my main cooling fan, and I have a secondary fan installed for aux. cooling when the AC is on.  Where do I tap into in order to pull a relay to gnd and activate my secondary fan?  Should I just tie into the compressor control plug? (I doubt that's the answer!)

Any help is appreciated!

Chris Adkins
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on February 01, 2016, 08:22:19 AM
Hey Chris

Your answer is in your original installation tutorial or post 3 above. Specifically:

Optional Connections

1.   This design includes the ability to provide a GROUND to a fan relay coil when the A/C switch is pressed as well as provide a path for PCM control of that fan without interfering with the PCM. The idea being that the fan will provide additional cooling for the condenser when the car has the A/C running in stop and go traffic.
2.   Most fan setups involve the PCM to provide primary control of the fans.
3.   In the setup mentioned in the above step the PCM has two wires that lead to 2 or 3 relays to control high and low speeds.
4.   The PCM grounds the low speed wire to enable low speed operation and also grounds the high speed wire to enable high speed operation.
5.   The way the fan function works in my kit is that it passes commands from the PCM through its wiring, but also has the ability to override these commands and turn the fan on by itself when the A/C button is installed.
6.   To install this feature:
   a.   Severe / Cut the low speed wire connection between the PCM and the Low speed relay.
   b.   Splice the A/C Controllerís Orange with Black strip wire to the wire leading back to the PCM. It is recommended that this connection be soldered and heatshrinked or butt crimped and heatshrinked.
   c.   Splice the A/C Controllerís Black wire to the wire leading out to the low speed fan relay. It is recommended that this connection be soldered and heatshrinked or butt crimped and heatshrinked.

In other words, you have a pair of wires coming out of the LSX AC controller. One Black and one that's Orange/Black. The Black wire is what you'd use to ground the coil of your aux fan relay. The logic for when it grounds is as follows:

Black = Ground IF AC Compressor = ON OR Orange/Black = Ground.

So your aux fan relay will come on when you press your AC button as long as the black wire is connected to your aux fan relay coil (and the other side of the coil is connected to 12v of course). The orange/black wire doesn't even have to be connected, it's just a wire that's available for your PCM in case you want to also tell the aux fan to come on when your coolant temps rise above the PCM's coolant sensor setpoint. If it's connected the PCM can also ground the black wire which can ground the aux relay coil WITHOUT the AC even being on. My schematic and wiring simply allows BOTH the AC system and the PCM access to the aux relay without interfering with each other.

Hope that answers your question.

Lane

 
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Mysta Joe on February 01, 2016, 08:58:00 PM
Hey Lane, just a quick question. Does it have to be a micro and mini relay or can it be two micro?

Just sometimes in Cayman stuff isn't always available and paying shipping and duty on the items will cost me 2-3 times more than initial cost.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on February 02, 2016, 08:37:21 AM
Hey Lane, just a quick question. Does it have to be a micro and mini relay or can it be two micro?

Just sometimes in Cayman stuff isn't always available and paying shipping and duty on the items will cost me 2-3 times more than initial cost.

Maybe

I may be able to handle the load. It may not. Most GM diagrams I've seen fuse the AC compressor clutch for 15-20Amps. That's a tough continuous load like a fuel pump and not something like a defroster or pop-up headlights that use a good bit of current but are only used for minutes at a time. In my experience, micros can handle 25A just fine... for a while. Higher continuous loads seem to burn them out over time simply because they're small and their inability to dissipate heat breaks them down over time.

So I'll circle back to maybe. Maybe is usually something electrical engineers avoid when designing electronics. We'd much rather use a component that will definitely do the job and will do it well indefinitely. A mini relay can definitely do the job in this application, whereas a micro is a toss up.

I can understand the struggle being in a remote location. One suggestion would be to simply use whatever 12V relay you can find locally that's rated for 30/40 amps. The only reason I use the relays I do is because I have pretty sockets that link them together and look nice. The design doesn't require a particular type of relay as long as it's rated for the load and the coil is a 12v coil. The only thing you'd lose is a little loss in the looks department.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ccadkins1 on February 02, 2016, 08:52:42 AM
Lane,
THANK YOU, THANK YOU, THANK YOU, THANK YOU, THANK YOU, THANK YOU, THANK YOU, THANK YOU, THANK YOU, THANK YOU!!! :cheers:
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Mysta Joe on February 02, 2016, 10:31:56 AM
Thanks for the reply and suggestion  :cheers:
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: dtsan on July 04, 2017, 06:15:09 PM
You are my hero! Had to revive from the dead just to say that.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on July 05, 2017, 09:35:34 AM
You are my hero! Had to revive from the dead just to say that.

Glad to be of service.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: AZieger on May 06, 2018, 02:52:14 PM
So I realize this thread is kinda old, but I am working on implementing one of these kits into my LS3 swap and I have a question -

Why do you only have the low speed cooling fan activate within the RPM window?  From what I understand, the original RX-7 wiring would turn on the low speed cooling fan continuously as long as the A/C button was pressed (and the thermo switch was closed, and the blower fan was on of course).  Is there a particular reason why we want to turn the cooling fan off at 4800 RPM?  I thought most cars kept a cooling fan running for A/C regardless of RPM.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on May 06, 2018, 04:37:41 PM
It's a rough way of disabling the fans at speed since all the controller has access to is rpm feedback. The idea is that at a certain point the air rammed through the condenser at speed > the spal fans capacity. At such point the powered fan actually serves as extra resistance to the incoming air.

Without digging back into the fsm I'd say you're probably right about the fd not cutting the fans at speed, but its something you see a lot of in modern cars.

Hope that helps
Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: AZieger on May 06, 2018, 04:47:46 PM
Sweet, thanks for the fast response!  The logic is a little fuzzy, since RPM isn't really indicative of vehicle speed.  But you could look at it as another way to help get every last peak HP by reducing alternator load at high RPM!  Sounds like it would probably work fine either way - I just wanted to make sure I wasn't missing something.

Another oddity that I am trying to figure out is why the factory wiring in AT cars (like mine) bypasses the HVAC thermo switch for cooling fan control.  So in other words, the ground path for turning on the low speed engine cooling fans are:

MT: Thermo switch>A/C button>Blower Motor
AT: A/C button>Blower Motor

Any ideas?

Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on May 06, 2018, 05:06:12 PM
Agreed. Rpm is definitely not 1:1 with speed. It's just all I had to work with (without adding another black box) and my thinking was that after 4800 your either on your way to the redline or at least not  puttering around / city driving.

To my knowledge and my understanding of the fsm, stock AT AC control does not bypass the thermoswitch, nor is the thermo switch the first part of the signal. If you want to get technical its the blower switch - > ac switch - > thermo switch - > ECU and Relays. It's gone over in more detail in the 'how it works' section of this thread.

Actually its been a bit since I've looked at the aux AT pages of the fsm but from memory there's only one version of the climate control page in the fsm. Not two different ones for AT and MT. Likewise, I approached MTs and ATs identically when i used to build these kits for people years ago and never had issues.

If what you're describing is actually how yours is wired, it's not factory or its a year we didnt get in the US in which case all bets are off :P

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: AZieger on May 06, 2018, 05:16:36 PM
You are correct, there is only one climate control page.  There is some "dashed" wiring shown on it though, and it matches the wiring in my USDM '93 auto.  The relay control wire that turns on my low speed fans is violet/purple, instead of violet like it is in the MT cars.  So it appears that AT cars bypass the thermo switch (see attached).

You are also correct in stating that it would not affect your customers if they follow your instructions.  I am doing it a little different, I am trying to re-use the fan control wire that is already in the harness (violet/purple in my case) just to keep things clean and prevent me from having to run more wires to my fan relays and/or open up the front harness along that whole length. 
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on May 06, 2018, 06:13:43 PM
Oh yeah. The dashed wiring. I guess my rust is starting to show + the fact that I've been replying from my back porch with a drink in my hand and going from memory up to this point  :cheers:
I'll have to agree with you. It does look like a bypass in the FSM, but I would be very surprised if it actually is that way in a physical sense. The thermoswitch is integral to stopping the evaporator from icing up on any car. If I had to guess the lower dashed line is a FSM error and the it's actually just showing a pickup after X-07 as shown on the left path and it's just showing an AT specific offshoot to a ECU input on the auto ECU that gets feedback when the AC is on. It may be that the color of the wire going to the fan relay is V for MT or V/P for AT but I suspect both go through the thermoswitch. That's the only reason I can come up with in my slightly inebriated state. Otherwise, I don't think Mazda would have shipped AT FDs with thermoswitches (which they did) if they were simply bypassed.
FSM errors are not common, but I definitely wouldn't consider it infallible. I think I've personally found and confirmed 2-3 (retract relay comes to mind) errors myself. I'd say the only way to really get to the bottom of this 100% is to do some continuity testing.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ls3_rob on May 07, 2018, 05:30:21 PM
Ok Lane here is a dilemma for you to help solve. My fan relay literally burnt up in my fuse box (30 side, 87 and 87a look like they got hot too). The wiring and fuse were fine  :scratch:

I am using the gmpp plug an play e67 harness kit for my ls3, samberg spal fans (2) and your ac ls3 wiring kit

I have used your ac wiring kit and it worked great for 2 years until it left me stranded overheating (no fan control).

I have the Samberg fans wired together using the single wire labeled fan from the fuse box and the other grounded to the chassis.

Am I pulling to much amperage for the 35amp provided in the gmpp fuse box?

I have put a 40amp relay in there with no problems since.

 :banghead:


Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Cobranut on May 07, 2018, 09:10:48 PM
Ok Lane here is a dilemma for you to help solve. My fan relay literally burnt up in my fuse box (30 side, 87 and 87a look like they got hot too). The wiring and fuse were fine  :scratch:

I am using the gmpp plug an play e67 harness kit for my ls3, samberg spal fans (2) and your ac ls3 wiring kit

I have used your ac wiring kit and it worked great for 2 years until it left me stranded overheating (no fan control).

I have the Samberg fans wired together using the single wire labeled fan from the fuse box and the other grounded to the chassis.

Am I pulling to much amperage for the 35amp provided in the gmpp fuse box?

I have put a 40amp relay in there with no problems since.

 :banghead:

Both those fans in parallel are way too much for one relay.

I used 3 40a Bosch-type relays for my fans, wired to allow two speed operation the way GM did originally.
There is a heavy gauge Blue wire in the front harness, that fed the original fan relays from a HD fuse in the front fuse box, that I used to feed the fan relays.

These, along with the other needed relays that replaced those in the front relay box, are mounted inside my Samberg radiator housing, on either side of the air filter.  Mount the tab facing up so water cannot accumulate in the relays.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on May 07, 2018, 09:28:16 PM
Yeaaah. @Cobranut beat me to it. You're just dealing with a load that's > your wiring / fuse / relay capacity. Back when I used to build fan controllers (http://www.halfspec.com/downloads/rx7/Fan_Controller_Installl.pdf) I used 10AWG and a 25A fuse to run each fan. To do that with one wire / fuse / relay for a continuous 50Amp load you'd need 8 or 6AWG wiring, a 50A fuse, and a 50+ Amp rated relay. Seriously doubt your gmpp harness kit has 8AWG in in  :(

Now to be completely honest, my experience showed that the fans only really draw ~20amps at full speed. I just build in 25% overcapacity in my wiring / fusing because every fan is a little different and startup transients usually produce a spike that > 20amps.

Finally, just so everyone's on the same page. The AC controllers in this thread and the LS1 controller thread only provide coil control to the end user's fan relay of choice. The AC controller can turn on a 1amp rated relay. The fan controller can turn on a 80amp relay. It's up to the end user to choose the correct relay / wiring for his/her load. The AC controller simply turns the relay on/off. It can't burn up wiring and/or relays. :cheers:

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on May 15, 2018, 09:30:18 AM
Something I whipped up for Rob via PM that I thought I'd share in case other people have similar questions about safely handling ~40amps of fan load:

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXACControl-2fans.jpg)

It's just the LSX AC circuit in my first post with fan fusing, switching, and wiring added to show how 2 fans could be safely powered with a GM fan output + the AC controller fan output. This is catered to Rob's specification of one wire fan control so there's no low / high speed operation, but it is a nice way to do it since you have independent relays. I.E., if one relay melts, blows up and/or its fuse blows, the other fan should keep on trucking.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Jakewah on June 12, 2018, 09:19:56 AM
Heads up to everyone, baker electronix is going out of business and it seems that the RPM Window Switch RWSR is no longer available for purchase:

http://www.bakerelectronix.com/products_rws/ (http://www.bakerelectronix.com/products_rws/)

Does anyone know of a drop in replacement?

Here are the specs Halfspec recommends in his parts list:

Reccomended Order Parameters = V8 LS1 Engine with a 2 pulse/rev Tach Signal
Enable RPM = 400 RPM (just under normal idle speeds) Disable RPM = 4800 RPM.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on June 12, 2018, 10:45:34 AM
Intellitronix / Summit Racing window switches will work. They're just more $
https://www.summitracing.com/parts/izl-n3210 (https://www.summitracing.com/parts/izl-n3210)
https://www.summitracing.com/parts/sum-830452-1 (https://www.summitracing.com/parts/sum-830452-1)

I used them on v1 of my controller with no problems. I'm sure there are 10-20 people still riding around with them.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Jakewah on June 12, 2018, 10:54:47 AM
Woohoo!! Thanks so much and thank you for somehow continuing to help our community out :)
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Negrok20r on July 30, 2018, 12:12:52 AM
1.   Plug the 25A fuse into the 12V Switched wireís fuse holder which is near the relays in the passenger kick panel area.
2.   If your system isnít charged and your pressure switch isnít installed, youíll have to jump the pressure switch connector with something line a non-insulated (bare metal) paper clip. The pressure switch used with the LS2/LS3 kit is simply a on off switch and has no polarity. It stays closed when the pressure is right in the system and passes the signal through it. It opens up when the pressure is too low or too high and breaks the signal passing through it.
So, to test without actually having the system charged up and the pressure switch installed, you have to jump the two terminals on the pressure switch connector with something like a paper clip.
3.   Turn your key to the ON position (donít start the car yet).
4.   Check the RPM switch to see that its indicator LED turns solid blue then starts to pulse blue.
5.   Crank your car and verify that the RPM switchís main indicator LED turns slightly purple. This indicates that the switch is accepting the RPM signal from the PCM and adds some red light to the indicator LED which signals that the switch is allowing the AC to be turned on (IE the carís RPM is within a safe range). If you turn off the engine or rev over 4800 rpm you will see the the main LED turn back to solid blue (indicating that the RPMs are too low or too high for the AC compressor to be on).


RPM switch with purple indicator light (car on and idling)

6.    With the car still on, turn on your A/C blower motor, then press the A/C button. You should hear at least one of the relayís click or at least feel it click if you touch it while toggling the A/C switch. You can also check the compressor clutch connector with a voltmeter (if you happen to have one) and youíll see 12v. Additionally, if you have hooked up the fan control wires, you should hear and see your fans turn on. If it does youíre done with the exception that you may need to reconnect your compressor plug and pressure sensor plug if you unplugged them for testing.
If not, check the unitís 25A fuse. If the fuse is intact, check your ground terminal. If needed, clean the contact point again. If that fails, move the ground to another location. If it still doesnít click when pressing the A/C switch please post your questions here and the norotors member will help you.

Ok . After long 3 years I decided to install the ac, I did all the above and it worked great. But as soon as I changed the system and I turn on the ac the fuse on the lsx control blow.
I replaced the fuse and disconnected the compressor and  turn it on again and the fuse doesnít blow. But as soon as I connect the compressor again the fuse blow .
Then when the switch is accepting the rpm , when I rev the car the light indicator becomes solid blue at 2200 rpm instead of 4800 rpm? Antrying before 2200 rpm is purpleish.
I double check all my connection and directions in here and I did everything accordingly ..
Any one that had similar problems? Or have any idea as to what's going on?
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on July 30, 2018, 01:52:14 PM
I'm pretty sure you've diagnosed a bad AC compressor clutch. I'd have to dig through my PM's but I'm pretty sure this happened to 2-3 people years ago when I used to sell the kits. When the clutches fail they hard short which blows your fuse.
If you wanted to be completely sure, you could hotwire in something small to the compressor plug like a turn signal or a car horn or something like that. The idea being that you could turn on the device as if it was the compressor and you would know that the AC controller is supporting a normal load correctly.

For the RPM window switch... What engine and gauge set are you running this on again? Normal LS engines have a tach output of 2 pulses / rpm and is what I had all the switches I ordered from baker electronix programmed for. So a 4800 rpm signal would be a 9600 PPS (pulse-per-second) signal. If you have a XYZ PCM that sends out 4 pulses / rpm (normal in most other V8 applications), your PCM would send out a 9600 PPS signal at ~ 2400RPM. If that's the case, the only way I know around that is to have the RPM window switch reprogrammed (http://www.bakerelectronix.com/ (http://www.bakerelectronix.com/)) for a 4 pulses / rev application or buy a end-user programmable window switch. Unfortunately, Baker Electronix is closing from what I've heard :(

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: wickedrx7 on July 31, 2018, 12:30:00 PM
I'm pretty sure you've diagnosed a bad AC compressor clutch. I'd have to dig through my PM's but I'm pretty sure this happened to 2-3 people years ago when I used to sell the kits. When the clutches fail they hard short which blows your fuse.
If you wanted to be completely sure, you could hotwire in something small to the compressor plug like a turn signal or a car horn or something like that. The idea being that you could turn on the device as if it was the compressor and you would know that the AC controller is supporting a normal load correctly.

For the RPM window switch... What engine and gauge set are you running this on again? Normal LS engines have a tach output of 2 pulses / rpm and is what I had all the switches I ordered from baker electronix programmed for. So a 4800 rpm signal would be a 9600 PPS (pulse-per-second) signal. If you have a XYZ PCM that sends out 4 pulses / rpm (normal in most other V8 applications), your PCM would send out a 9600 PPS signal at ~ 2400RPM. If that's the case, the only way I know around that is to have the RPM window switch reprogrammed (http://www.bakerelectronix.com/ (http://www.bakerelectronix.com/)) for a 4 pulses / rev application or buy a end-user programmable window switch. Unfortunately, Baker Electronix is closing from what I've heard :(

Lane


Which AC compressor are you running?  I fried two clutches before realizing the pin out was flipped from previous years.  I am running a 2012 L99 accessories. 
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Negrok20r on August 02, 2018, 12:39:29 AM
^^ I have a 2013 ls3 compressor

And after checking the lsx harness ac connector with a light bulb , it seemed that is supporting the load correctly.
Next,  I checked the compressor and wires are flipped.
I'll replace the clutch tomorrow and see how it goes.
Rpm signal Im running holley dominator aND it's set up at 4pps I think. Idk if I can change it to 2pps I'll see, if not I'll get a Dakota box to do it .
Thank you guys .
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ls3_rob on October 10, 2018, 09:19:30 PM
Here is a new problem I noticed recently having used this kit just fine for 2 years now (using ls3 ac wiring kit with ls1 accessories and ls3 engine)

When the ac button is pushed the car at a stop will die or lose all electronics and when moving bucks like crazy/voltage fluctuates acts like it wants to die

The volts act like a bad alternator going from 14-8-10-12-14 back to 8 and the lights flicker and radio shuts off

I was driving around 10-15 miles and died/came back to life 4 times but only when ac was on. At a stoplight died completely

Already replaced ignition switch/battery/alternator to no avail

Problem stops when ac button is off

Already tried jumping the compressor connector to a light bulb and worked fine
Also tried jumping the pressure switch and compressor kicked on with no problems, ac clutch spins freely and all relays/fuses are good

No ideas at this point

Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 10, 2018, 09:37:11 PM
Does it make a difference if the compressor is unplugged? I.E. does it stall out when just the electronics are involved?
How about pulling the AC harness fuse?

You've done a good job starting to isolate the problem, but the two things above might help clarify the problem even more.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ls3_rob on October 11, 2018, 11:59:02 PM
Unfortunately, neither unplugging the AC fuse nor the compressor do anything to help the issue.

What I mean by that is everything voltage-wise stays normal except for the working AC of course.

I have attached some videos of the problem with everything plugged in and working as it has for the past 2 years.

Like I mentioned voltage will drop and even sometimes die. Ac is still cold and both fans blow as well as the AC clutch spin freely.

This problem happens intermittenely and not every time the button is pushed.

I do appreciate any ideas or help at this point.

Links of videos below:


https://vimeo.com/294711315

https://vimeo.com/294711198
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 12, 2018, 07:41:55 AM
Is that your radiator fan I hear kicking on every time you press the AC button? I mean, that's normal, it's just surprisingly loud to me. If so does your car behave the same way with the fans unplugged?

The only reason I ask is because I looks like you're browning out a cabin or lighting circuit (maybe your tns circuit) with a large transit load, which in this case may be your radiator fan depending on how you supplied power to it.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ls3_rob on October 12, 2018, 08:32:58 AM
I have it wired exactly like this: The unplugging of fan relays made the problem stop

(http://www.halfspec.com/pictures/OpenSource/LSXAC/LSXACControl-2fans.jpg)

Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ls3_rob on October 12, 2018, 08:41:23 AM
I unplugged all factory fd fan relays in the passenger fender well would that be a problem?

(https://i.ebayimg.com/images/g/lbgAAMXQO21Rxvu-/s-l1600.jpg)
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 12, 2018, 09:16:57 AM
Removing the stock fan relays wouldn't cause this issue. I'm more concerned with how you powered your relays and it may partly be my fault due to the diagram I created. Specifically, the fan relay's really don't need switched 12V to operate correctly. Getting 50 amps of switched 12V is where I think the issue is as that's a tall order for even the ignition switch. I don't know where you decided to get that kind of power, but I would bet it's overtaxing where you tapped.

Consider this revised diagram:

(http://www.halfspec.com/pictures/AC/Help/LSXACControl-2fans-rev2.jpg)

The important bit being, that for a 50A load, you really need to go back to the battery directly, using 12Awg for each of the two fan relays.
You might give it a shot with temp wiring if that's easier, just to prove that's the issue, before you actually do it for real. Unless you're one of those nuts running a motorcycle battery or something, I think that should solve the problem.

If that's the issue, you have my apologies for time wasted. Your diagram was one of a few I crunched out back to back a few months ago, and that was a careless error on my part.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 12, 2018, 09:58:52 AM
And when I say "need to go back to the battery directly, using 12Awg for each of the two fan relays" you don't actually have to go all the way back to the battery with two 12AWG runs. You could easily pickup that kind of power at the starter or alternator since you should have some beefy supply wiring feeding both of those.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: ls3_rob on October 17, 2018, 07:24:41 PM
Good News, Bad news

The Good News is that the og wiring you modified for me was indeed the culprit and now wired with 12v source instead of ignition using 12 gauge and 30amp fuses going to battery. It works without drawing too many amps and has yet to die/fail.

The fans kick on at 210 degrees and the ac will cycle on/off like it supposed to

The Bad News is the fans continue to run when the car is shut off. I have to put the key in the on position after shutting the car off to get the fans to stop running.  I can run a kill switch but is there any reason as to why they still run wiring them using the battery now instead of the ignition?

Thanks for all the help you do for me and the community
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 17, 2018, 07:48:11 PM
Well shit! That's another one on me  >:(

Take #3 (sorry its a mess with a bunch of 12V switched boxes, but I'm home alone with the kids):

(http://www.halfspec.com/pictures/AC/Help/LSXACControl-2fans-rev3.jpg)

While the main supply wiring that goes through the relay contacts can be straight to the battery, the topside of the relay coils (pin 86 in the diagram) need to stay on 12V switched to turn off when you pull the key. That way, even if the PCM is sending a ground out to tell the relay to stay on, the coil loses its 12V from the ignition switch, so it has no choice but to turn off.

Really sorry about the 2x mess-ups Rob. You try and help someone and make their life even harder  :-[
I guess that's what I get for getting out of the game and thinking I can still do what I used to do.

Related topic. All LS PCMs I've encountered do what yours is doing. It's kinda like a radiator fan turbo timer. The PCM outputs the fan ground as long as your coolant temp is above the setpoint even after power is removed from the PCM. Some people like it. Most think its weird. For the folks that don't like it / think it's weird, the diagram in this post should resolve the issue.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Cobranut on October 17, 2018, 09:36:57 PM
Lane,

I was looking at the diagram, and even if the PCM output opens, there was still another path through D2 and the compressor relay coil, back to sw12v, and all the other loads attached to that. I doubt the one relay would pass enough current to pull in the fan relays, but it could slowly drain the battery.

Feeding all the relay coils with sw12v should eliminate that possibility as well.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 17, 2018, 10:27:00 PM
Lane,

I was looking at the diagram, and even if the PCM output opens, there was still another path through D2 and the compressor relay coil, back to sw12v, and all the other loads attached to that. I doubt the one relay would pass enough current to pull in the fan relays, but it could slowly drain the battery.

Feeding all the relay coils with sw12v should eliminate that possibility as well.

No. That section of the circuit only deals with grounds. In fact, in my diagram the bottom side of the coils / Pin 85 is the ground side of all the relays for the sake of consistency. The top side / pin 86 is the only side that reacts to 12v. Feeding 12v to any pin 85 in my diagram wouldn't do a thing, since pin 86 would already have 12v on it and you'd have 0v of potential across the coil.

Respectfully, I think you're mixed up about the operation.

There are three states where the fan relay output gets a ground.

State 1 - The PCM orders low speed output due to hot coolant temps. Notice the polarity of D2 stops the AC compressor relay from receiving a ground.

(http://www.halfspec.com/pictures/AC/Help/lsxAC-state1.jpg)

State 2 - The RPM window switch is within its 'RPM window' and hence delivers a ground to pin 30 of the AC signal relay, while concurrently, the AC button is pressed, which gives a ground to pin 85 of the AC signal relay latching 30 to 87 and allowing the ground to activate the compressor relay. Note D3 stops the PCM's low speed fan output from receiving an external ground (gets you a MIL light and a fault code).

(http://www.halfspec.com/pictures/AC/Help/lsxAC-state2.jpg)

State 3 - States 1 and 2 occur simultaneously:

(http://www.halfspec.com/pictures/AC/Help/lsxAC-state3.jpg)

States 2 and 3 are where you can run into a problem with the LS PCM sending a ground to the Fan Relay output and keeping the radiator fans on even after the PCM loses power and they stay on until the coolant temps come down below the low setpoint. Delete the whole rest of the AC circuit and the LS PCM fan outputs still behave this way.

The original LSX AC circuit posted in this thread had the benefit of being endlessly bench tested on my own FD and after that, went out to ~50 of my own customers before I posted it here. Rob's diagrams were turned out in a few minutes while my kids were probably screaming at me ;)

Lane

Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Cobranut on October 18, 2018, 12:09:32 PM
I was referring to when the fan relay coils were connected to constant 12v.  The current path would be through both fan relay coils, through forward-biased D2, and the compressor relay coil back to sw12v, which when turned off would be pulled down by all the other switched loads in the car.

Supplying the relay coils with sw12v solves all the issues.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on October 18, 2018, 03:59:06 PM
David

You're right. With the diagram I drew for Rob containing the erroneous 12V constant on the fan relay coils, I can see how you could get a path through each parallel fan relay coil, through D2, through the compressor relay coil, and through whatever other load on switched 12V that ties back to ground when 12V Switched is switched off. I've never seen an automotive relay contact latch with < 6VDC on it which is what you'd get in this situation because you'd get at least 3 voltage drops on that path + the 0.7v diode voltage drop drop, but even without latching, I believe you're right that a parasitic path would exist.

My apologies for doubting your understanding of the circuit  :cheers:

For anyone else here reading, the takeaway it to always use 12V switched on the hotside of your fan relays if using my LSX AC Controller. By the time this post goes live, all the diagrams in this thread should be correct.

Lane
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Cobranut on October 18, 2018, 11:13:05 PM
David

You're right. With the diagram I drew for Rob containing the erroneous 12V constant on the fan relay coils, I can see how you could get a path through each parallel fan relay coil, through D2, through the compressor relay coil, and through whatever other load on switched 12V that ties back to ground when 12V Switched is switched off. I've never seen an automotive relay contact latch with < 6VDC on it which is what you'd get in this situation because you'd get at least 3 voltage drops on that path + the 0.7v diode voltage drop drop, but even without latching, I believe you're right that a parasitic path would exist.

My apologies for doubting your understanding of the circuit  :cheers:

For anyone else here reading, the takeaway it to always use 12V switched on the hotside of your fan relays if using my LSX AC Controller. By the time this post goes live, all the diagrams in this thread should be correct.

Lane

Thanks Lane,

Generally, it's always a good idea to use the same switched source for all relay COILS, that powers the device that triggers the relay.
If you're certain that the device floats all outputs when powered down, then this isn't necessary, but it's still a good practice.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: petawabit on March 09, 2020, 12:49:43 PM
Anyone have any pointers on depinning the black/yellow wire that goes into the connector on the back of the driver side fusebox? I'm not seeing a tang where I poke from the front side and looking at the new male/female connectors on the new harness, can only see an indented square at the bottom of the terminal.  Tried gently shoving a flat head underneath that section and prying upwards, while pulling on the back from the wire with no luck.  thanks in advance!
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Ottocycle on June 30, 2020, 08:11:35 PM
Hello everyone. I'm a new member here and signed on because of Lane's excellent tutorial. (Also his one on AC plumbing).
Thank you, thank you.

Let me say from the outset I am not an RX7 owner, but I am an LS swap enthusiast. I have a Volvo 960 wagon that I have completed a functioning 5.3 LS swap, without AC. I do not believe in re-inventing the wheel and have scanned the web to find solutions to issues I have encountered and wish to use Lane's excellent info for both my wiring and plumbing. I have learned a lot from this exercise and will learn a lot more before I'm done, thanks to people like Lane who choose to inform the rest of us.

I have a question regarding RPM limit switches. I have bought the other components for the wiring but am confused about the advertised ranges the RPM limit switches, since Baker's are no longer available. I checked on the Summit site and their switches run from a baseline of 1,000rpm, with no indication whether they can be adjusted lower to match specs. I contacted Intelletronix regarding their units adjustability but have had no response.

Does anyone know: (A) if the Summit switches can be adjusted to specs as they come from the vendor, or (B) can the input signal from the Chevy ECU fool the switch by intercepting it with a resistor or some other means.

Once again thank you for putting both tutorials together and if anyone has any insight into the questions please let me know.
Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: halfspec on July 01, 2020, 12:04:38 PM
Hello everyone. I'm a new member here and signed on because of Lane's excellent tutorial. (Also his one on AC plumbing).
Thank you, thank you.

Let me say from the outset I am not an RX7 owner, but I am an LS swap enthusiast. I have a Volvo 960 wagon that I have completed a functioning 5.3 LS swap, without AC. I do not believe in re-inventing the wheel and have scanned the web to find solutions to issues I have encountered and wish to use Lane's excellent info for both my wiring and plumbing. I have learned a lot from this exercise and will learn a lot more before I'm done, thanks to people like Lane who choose to inform the rest of us.

I have a question regarding RPM limit switches. I have bought the other components for the wiring but am confused about the advertised ranges the RPM limit switches, since Baker's are no longer available. I checked on the Summit site and their switches run from a baseline of 1,000rpm, with no indication whether they can be adjusted lower to match specs. I contacted Intelletronix regarding their units adjustability but have had no response.

Does anyone know: (A) if the Summit switches can be adjusted to specs as they come from the vendor, or (B) can the input signal from the Chevy ECU fool the switch by intercepting it with a resistor or some other means.

Once again thank you for putting both tutorials together and if anyone has any insight into the questions please let me know.


Welcome! Wagons rule!

Intelletronix is a POS company and I too have written them and have gotten zero response. That said, I have used their switches in previous generations of my LSX AC controllers:

(https://www.halfspec.com/pictures/AC/_GJW8409_zpscafc7369.jpg)
(https://www.halfspec.com/pictures/AC/ls2ls3control_zps895088e6.jpg)

First picture = N3210 which is what I think you've been looking at. The second picture is of the S3012 which I don't think they make anymore.
I have more experience with the S3012 and know it can go down to 100rpm activation. It's probably been 6 years since I took the picture of the N3210 and I remember less about it, but the fact that it's pictured makes me think I got it going.
The Intelletronix datasheet doesn't mention anything about a lower limit of 1000rpm, so I'd say that like the S3012, you should be able to get down to 400rpm no problem.

http://docs.wixstatic.com/ugd/6a4159_ee484d64d1434d8091113711320ad93c.pdf

Oh, and resistor's won't help you fool / manipulate the rpm window switch activation / deactivation points. The only thing that could help you, is changing the settings from a 4 cylinder to a 6 or 8 cylinder. Remember, the LS tach sensor outputs 2 pulses / rev like a 4 cylinder. It's NOT like normal V8's that output 4 pulses / rev:
https://www.norotors.com/index.php?topic=23631.msg334117#msg334117

Lane

Title: Re: Ultimate LSX AC Control Tutorial - HalfSpec Engineering
Post by: Ottocycle on July 01, 2020, 11:21:59 PM
Lane,

Thanks for the quick reply and info. I just ordered an RPM switch from Summit. (Its on backorder, perhaps by a few weeks). Hopefully I can make it work.
I will get going on the rest of the loom and get the plumbing sorted for now (as well as a warren of vacuum operated doors for the climate control system). I'm trying to make everything look as original and factory as I can.
Thanks again and I will keep you posted on my progress, assuming I don't need you to bale me out (no promises)!!!!!