I'm putting a 5.3 in my 85 Monte Carlo SS and will be using the a/c. If I hook up the a/c request wire from the pcm like it should be, will that make my fan come on when I turn on the a/c? I'm using a 99-02 f-body harness and f-body pcm.

 

My understanding is that AC functions are dependent on the f body pressure sensor.
I just used a trinary switch to control one fan.

 

Yes, it should, that is how mine is wired, and it brings both fans on when compressor clutch gets 12 volts....

T,

 

The pcm controls the a/c on an f-body system, but I have a g-body. My compressor is a fix displacement Sanden and the pcm doesn't have any control over it.

 

Thanks, That's what I wanted to hear. I want everything possible to be completly automatic on this car. I didn't want to have to wire in another relay to the a/c system just to make sure the fans come on.

 

You are the wiring guru...


The PCM is setup to turn the Fans on when the AC comes on..that's a default setting. You can adjust it with HP Tuners..as in what temp you want them to come on when you turn the AC on.

 

I'm getting closer to having it running. I didn't like my gauge setup so I changed that last night. They are a lot easier to see now. I have my exhaust system, but it's still laying in the corner. I just need to get it put on, get a drive shaft cut, and do a little more wiring and I could start it. It sure looks a lot better with the fresh paint.

 

Yea..it's coming along..

 

The PCM will engage the fans and bump the idle up as long as pin#17 red sees a 12v signal and red pin #55 sees a ground signal.