Category Archives: DIY

SR20DET A/C Wiring in S13

I’ll be collecting my notes on wiring AC that has been installed on an SR20DET in my S13 (1990).

My Setup…

  • 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.