When looking at the 1999FullWiring.pdf, I think there could be some clarifications and corrections on C220.
Here's the way I understand it.
C220, pin A - TAN - Oil pressure indicator Lamp Output. I don't think we actually use this. The RX7 sending unit connects to grey w/red stripe wire on X14.
C220, pin B - GRY - (for Manual transmission only)
C220, pin C - PNK - Fused Output - Ignition (for Electronic Auto. Transmission - 4 Spd only)
C220, pin D - PPL - (for Electronic Auto. Transmission - 4 Spd only)
C220, pin G - BRN - 15A fused Output - ignition - (Source feed for Manual Transmission, backup lights)
C220, pin H - LT GRN - Backup light feed (for Manual Transmission, backup lights turn on when in reverse gear)
I have yet to do my swap, so am I wrong?