I’ll be collecting my notes on wiring AC that has been installed on an SR20DET in my S13 (1990).
- SR20DET Red Top
- A/C Lines – S13 DOHC
- A/C Compressor – S13 DOHC
- A/C Condensor – S13 DOHC
- A/C Evaporator Core – S13 DOHC
Condensor Fan & Idle Bump Wiring
When the A/C is on, your ecu needs to bump up the idle to compensate for the extra load.
S13/S14 Body Harness Pins (may have to be translated to S13 colors)
- 16 (yellow/black) – A/C Switch
- 46 (black/pink) – Tripple Pressure Switch (Thermo Control Amp)
- One of the blue/green from S13 harness? - Thermo Control Amp?
- 41 (KA F3) (blue/green) – Cooling Fan Low Signal
- 25 (KA F3) (orange/blue) – Cooling Fan High Signal
S13 SR20DET ECU Harness
- 41 (blue/green) – A/C on Input (Air Cond On from A/C Panel)
Fans & Idle
This will get the ecu to turn on AC mode, kick up the IACV and turn on the AC fan.
- Connect pin 16 (yellow/ black from Body Harness) to pin 46 (black/pink from Body Harness) and pin 41 (blue/green from ECU Harness).
- Connect pin 41 and/or pin 25 to one of the blue/green from the S13 harness. (this gets the fan to run on LOW/HIGH)
” on the f3 conector (big white plug under dashboard near passenger foot well , you know the one you have to splice into to make your engine swap work) you need to splice together the following cables pin 16 yellow/ black to pin 43 or 46 (cant remeber now im at work) black/pink. and what do you know voila it works, push the a/c button a/c turns on, pust it again it turns off.”
This is what I did, except I spliced in the wires for the IACV and the hi/lo fan. This us using the KA compressor.