Air Conditioning Signal
WARNING: This page is about a different car, the 1992 Acura Legend. However, it is still accessible from the selected car via links, so may be relevant.
- Connect PGM-FI test harness between ECU and vehicle harness. Unplug connector "C" from main harness only. DO NOT disconnect from ECU. Turn ignition on.
- Measure voltage between ECU terminals C3 (positive) and A26 (negative). If voltage is not about 10 volts, substitute a known good ECU and recheck voltage.
- If voltage is about 10 volts, reconnect connector "C" to main wiring harness. Momentarily connect terminals A15 and A26 together and check for clicking of A/C clutch.
- If A/C clutch clicks, go to next step. If A/C clutch does not click, jumper Red/Blue wire of A/C clutch relay connector to ground. If A/C clutch clicks, repair open in Red/Blue wire. If A/C clutch still does not click, repair A/C clutch circuit.
- Start engine, and turn blower on. Turn A/C switch on. If A/C operates, A/C signal is okay. If A/C does not operate, measure voltage between terminals C3 (positive) and A26 (negative).
- If voltage is more than one volt, repair open in Blue/Black wire between terminal C3 and cooling fan control unit. If voltage is less than one volt, substitute a known good ECU and recheck voltage.