I dont think my fans automatically come on with the A/C and I thought that they were supposed to. If they are, what could be causing them to not come on with the a/c, yet they still opperate normally otherwise and all the relays are good.

-James

 

I think the F-body is the same as the Y-body.

On the Y-body, the cooling fans are controlled by:
1) Coolant temperature
3) Oil temperature
3) A/C high-side pressure ( this equates to condensor temperature)
4) Limp-home mode of the ECM -- the fans run all the time, regardless

The ECM can turn off the fans regardless of sensor readings after the vehicle reaches a certain speed -- I think this is about 40 mph.

When the A/C high-side sensor senses a pressure above a certain point, the ECM turns the fans on -- this happens most of the time the A/C is on.
The cooler the ambient temperature is the less the fans will be activated by the A/C.

Tom Piper