Hey new member here and im hoping to get some advice on the air conditioning in my 99jimmy slt trim bought the truck for 600 dollars with a bad engine but i have a99 blazer that was totalled last year and i paid to have the engine from that truck transplanted since it was rebuilt just prior to getting hit anyway the engine is in the jimmy now and running well however I m trying to get the ac working and as it sits it will not turn the compressor on ive checked fuses and powered the clutch on with my power probe and it blows cold air so long as the clutch is powered so i think i have a control problem When the truck is running the ac light is onbut i need a wiring diagram so i can say for sure thats the problem also have a friend who works for a gmc dealer who may be able to get his hands on a tech 2 for a day or so i intend to fix this qnd make a daily driver of it I've searched and apparently the ccc is a common problem hoping maybe one of you has some advice and thanks in advance

 

Just wanted to add that it doesn't seem to switch modes warm air blows from the dash vens only no matter where the controls are set

 

Have you checked the amount of refrigerant in the system? If the motor was transplanted, I would assume you would have to disconnect the AC system from the compressor.

 

Yes i have the equipment to evacuate and recharge the system just no compressor command wit the controller set to auto

Thanks for the inquiry though

Just this evening I evacuated the system and recharged it because the last time the high side port leaked all the freon out put a jumper wire in place of the relay and the compressor comes on and makes cold air however it still won't run off the relay which ive swapped numerous times with a known good one does anyone know if there's anything else besides the control head that commands the compressor on?

 

No one has any suggestions? Guess ill replace the control head and hope for the best