My 87 RX AC compressor has 3 wires going to it. I understand ground and 12v but what would the third wire accomplish? Basically my AC is not working. I checked the freon charge and it looks good, next I tried to hotwire the AC compressor to see if the clutch engages but I dont know know which wire to use. Any ideas?

 

Thanks,

Gregg

if im not mistaken there are 2 wires that will go to the sensor on top of the compressor and another single wire (blue?) that applies power from the relay to the coil and is case grounded.

looking at diagram from an 85 right now 87 should be similar. I can check one of my cars in the morning if need be.

I just double checked my AC wiring. I have a total of 5 wires.

 

- 2 wires go to the pulser sensor on top of the AC pulley

- 1 blue wire to AC Compressor (with its own harness connector)

- 2 wires to AC Compressor (1 blue and 1 black from a different harness connector)

 

Any ideas?

 

Thanks,

Gregg

I was able to hotwire the AC using the single blue wire and it blows cold. Now I need to figure out why the compressor clutch is not getting 12 volts. I still have no clue what the other 2 wires to the compressor are for.

 

Time to start a new thread......see if anyone can assist in AC problem.

pressure switch?