oldgoat69

The plan is to trigger the PCM when the AC is switched on to step up the idle and activate the fan.

I see 3 pins in the blue connector referenced.

Pin 26 = A/C pressure signal
Pin 30 = A/C pressure +5
Pin 55 = A/C pressure signal

I have 2 terminals on the pressure switch, #1 12v in, #2 12 v to compressor. I understand that I need to use the #2 terminal for the signal. To which PCM pin do I connect?
My guess is not Pin 30, what do Pin 26 and Pin 55 control?

BigEd_72455

iTrader: (7)

Send a message to Brendan over at LT1swap.com and he should be able to tell you what you need to know.

sick_46

iTrader: (3)

I too would like to know the answer. please post it up here if you figure it out

oldgoat69

Brendan does not support the E40, I asked him first. After a bit more research it appears that Pin 26 is the one to trigger. I will try that and post the result.

oldgoat69

I have verified that Blue Pin 26 is correct on the E40 PCM. The circuit # is 380 and seems to be universal. On the GMT800 blue/green PCM it is Green 14.

BigEd_72455

iTrader: (7)

Congrats and good work on chasing down this info. See if you can get a mod to pin it to the top or maybe make it a sticky.