AC Problem

Not enough air thru condenser, try cleaning. Maybe too many bent fins.

 

Does the engine fan cycle on and off when parked with AC on?
If not it is probably the trianary switch.

 

Run engine fan, recirculate the air instead of fresh draw.

 

Surely pete has a manual fan switch and you turn it on when parked? Are the rad cac and condenser clean? I mean really clean not just looks clean and no junk in between them. Sharp truck what year is it?

 

Yeah,clean all the bugs out,deep down in the condenser fins.

 

I'm assuming your clutch on the fan works by air pressure. I would pull the hose off at the clutch and turn the manual switch on and off to make sure there is air pressure. If there is then I would replace the clutch on the fan.

 

And by the way. My engine is a Detroit. I can do that test with the engine off and the key on. My engine requires air for the fan to turn on. Most turn on by a lack of air pressure. With the engine off and the key on I can do the test with the manual switch and turning the fan by hand.