Outer Limits 4x4 Board

Hi
Running a 91 3.9 rangie on megasquirt ( going well ) . Anyway its time to sort out the airconditioning . The old ecu had an input from the aircond system and put an output etc . I am guessing the input triggered the aircond compressor and an idle change maybe .
I am about to sit down with the wiring diagram and sort it out but though I would ask if someone know what it was .
ie , pos in and pos out so just a jumper wire . Or something stupid like a pos in looking for negitive out etc .

Cheers
Chris

Well to answer my own question in case anyone else does this . the input to the ecu from the aircond is +ve volts I had about 10 volts so safe to say 12 v from a good battery . the bugger is the output to the compressor clutch is an earth so I will have to put a relay in there to switch it over . Still better than no a/c , while I've got it may as well use it .

Cheers

Chris

Good work, I didn't know the answer but knew that there was an input required for the car to run the ac, I learned this when I tried to cut the ECU out when running on LPG - I did that and no air con

Tom