January 20, 2021, 08:02:52 AM

Author Topic: Warm positive battery terminal  (Read 2348 times)

Offline cholmes

Re: Warm positive battery terminal
« Reply #60 on: December 24, 2020, 06:17:46 PM »
Yes, the sense wire exists on stock alternators, and is a separate wire from the excite wire.

The wire connected to the resistor or dash lamp is the excite wire.

Offline Cobranut

Re: Warm positive battery terminal
« Reply #61 on: December 25, 2020, 01:29:14 AM »
Gunny, the most foolproof place to put the sense wire is directly on the battery positive post. Realistically, the battery cable post on the starter is fine too, and typically easier. Of course, this does assume the battery cable, and its lugs, are in top shape.

As far as it firing back up fine, maybe you have solved the problem. Carry your voltmeter in the car for a while, if you do get a slow start, you can check the voltages again.

Alhadra, I agree, with your alternator output directly tied to the battery like yours is, the "sense wire" in your setup is at the battery. I also agree about the higher voltage helping things in general; as long as the battery can take it, everything in general works better with higher voltage.

Back to battery cables. They can look perfect, but corrosion can form between the lug and the cable. Anytime electrical problems come up, peel back any tape or heat shrink and look where the cable goes into the lug. Any trace of green is trouble; that's corrosion, and the lug and / or cable needs replacing.

Finally, I'm sure none of you have this, but I've seen aluminum battery cables before! Absolute crap, and my old FB came with one stock! Predictably, it failed, at the lug.

If you get a great deal on a battery cable (aluminum is cheap compared to copper), peel back the covering where the cable goes into the lug. If the cable is silver, and the lug is crimped on, then the cable is aluminum. The cable in soldered lugs may be silver from the solder, and you know it's copper cable, because aluminum cannot be soldered to copper or brass lugs.

In buying wire, I've noticed a lot of copper-clad aluminum wiring on Amazon, eBay, etc. of late.
You have to read the fine print to be sure it's actually copper wire.
Stay away from the ridiculous priced audiophile wires though.  Good quality welding cable is excellent for making battery cables.
1995 FD, 7.0 Liter stroked LS3, T56, 8.8, Samberg kit.

Offline cholmes

Re: Warm positive battery terminal
« Reply #62 on: December 25, 2020, 02:38:26 AM »
Wow, I didn't know about the copper-clad aluminum wire, that's good info, thanks.

And you're right, the "ultra pure" audiophile wire is pure marketing b.s., and yep, I agree, good welding cable is the best bet for battery cables.

Offline 65imp

Re: Warm positive battery terminal
« Reply #63 on: December 25, 2020, 04:41:53 PM »

After learning this, I switched my alternator and voltage regulator out for a DR44 with a self-exciting 14.7V regulator.


Where did you get yours?  I have ordered them in the past, but I got a lot of old cars that want the 14+V.  But you are right, all the factory alternators dink around with ~13.6 voltage.
absolute power corrupts absolutely  :yay:
93 FD widebody - destroked
69 Suburban - positive manifold pressure
72 Blazer - 6.0, 6speed 4wd
65 Impala - 5.7
59 cad  - 5.3
53 spartan - crash pad status

Offline AHarada

Re: Warm positive battery terminal
« Reply #64 on: December 25, 2020, 08:03:49 PM »
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Offline jwvand02

Re: Warm positive battery terminal
« Reply #65 on: December 26, 2020, 10:34:09 AM »
Gunny, the most foolproof place to put the sense wire is directly on the battery positive post. Realistically, the battery cable post on the starter is fine too, and typically easier. Of course, this does assume the battery cable, and its lugs, are in top shape.

As far as it firing back up fine, maybe you have solved the problem. Carry your voltmeter in the car for a while, if you do get a slow start, you can check the voltages again.

Alhadra, I agree, with your alternator output directly tied to the battery like yours is, the "sense wire" in your setup is at the battery. I also agree about the higher voltage helping things in general; as long as the battery can take it, everything in general works better with higher voltage.

Back to battery cables. They can look perfect, but corrosion can form between the lug and the cable. Anytime electrical problems come up, peel back any tape or heat shrink and look where the cable goes into the lug. Any trace of green is trouble; that's corrosion, and the lug and / or cable needs replacing.

Finally, I'm sure none of you have this, but I've seen aluminum battery cables before! Absolute crap, and my old FB came with one stock! Predictably, it failed, at the lug.

If you get a great deal on a battery cable (aluminum is cheap compared to copper), peel back the covering where the cable goes into the lug. If the cable is silver, and the lug is crimped on, then the cable is aluminum. The cable in soldered lugs may be silver from the solder, and you know it's copper cable, because aluminum cannot be soldered to copper or brass lugs.

In buying wire, I've noticed a lot of copper-clad aluminum wiring on Amazon, eBay, etc. of late.
You have to read the fine print to be sure it's actually copper wire.
Stay away from the ridiculous priced audiophile wires though.  Good quality welding cable is excellent for making battery cables.
Yup, welding cable only. It comes with the added benefit of already coming with good heat-resistant insulation too. I want to add that lugs that large need to have a hydraulic crimper. Harbor freight has one that works fine for the home gamer.

I mentioned earlier I had very similar issues (car would be okay for a bit, heat up, stop charging, battery completely dies in traffic) and it was because PO built the battery cables out of aforementioned CCA audio wire and put the lugs on with a hand crimper or a hammer. I chased all kinds of alternator wiring stuff before finally just fixing the obvious issue.

Offline Gunnytron

Re: Warm positive battery terminal
« Reply #66 on: December 28, 2020, 05:07:12 PM »
Driven the car a few more times now and still not had any starting issues. It did crank for longer than usual before starting today, but that is more likely a tuning thing.

Just to note that it might also be worth checking the alternator is grounded properly. I also painted that and the mounting brackets so I will make surer there is good contact there too.
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 8.8, 31 spline, trac-loc 3.55 Diff, Holley HP EFI, Racelogic TC.

Offline cholmes

Re: Warm positive battery terminal
« Reply #67 on: December 28, 2020, 10:19:58 PM »
That's a good point about the alternator grounding, a poor ground there will certainly affect charging.

Offline Exidous

Re: Warm positive battery terminal
« Reply #68 on: January 05, 2021, 12:05:43 AM »
So Gunny, to ease your mind on the loose bolt...I was having cranking issues with the new motor. The 51r yellow top didn't have the cranking amps. My engine grounds were soldered by the previous owner and melting at the current load.

4ga 100% copper welding wire, proper crimps and an antigravity 900+ CA lithium makes the car spin VERY well.

I'm running a DR44 alternator that is now controlled by the megasquirt. I can even see the load on the alternator. After charging even the beastly DR44 will pull 57% load at idle to charge. I'm only going to 14.3-14.4 though.

I had issues getting the MS3 to talk to the alternator. Turns out the Digital I/O don't like pull-up resistors. Was only getting 1.7v on my mini oscope.  Moved to a true PWM output and get a proper 5v p-p.

And after all that...I forgot to connect the main engine harness sensor ground directly to the battery...or at all. Just dangling there. Somehow the car still ran but I was getting sync errors from the cam sensor. Connected it back up and all is well.

Oh ya, and the new 440ci freaking rips. Still not past the scurred stage.
94 BB Sleeved gen IV LS7, MS3ProU with TC, RONIN 8.8 and LT's with custom 3.5"single to VAREX muffler.

Offline Gunnytron

Re: Warm positive battery terminal
« Reply #69 on: January 19, 2021, 05:48:33 PM »
*edit* Posted in wrong thread
« Last Edit: January 19, 2021, 06:23:50 PM by Gunnytron »
http://www.norotors.com/index.php?topic=12880.0
FD, LS1 running 220 3.90 Trickflow heads, Comp Ultra-gold Arc 1.72 Rockers, 7.550 BTR Pushrods, BTR Stage II NA Cam 227/234 .614"/.576" 113+2, ARP Head Bolts, BTR Platinum Springs, Ported FAST 90, NW 90mm TB, FAST 60lb Injectors, Textralia Clutch/Flywheel, T56, Cobra 8.8, 31 spline, trac-loc 3.55 Diff, Holley HP EFI, Racelogic TC.