Everything works on the AC settings except compressor will not come on. I have tried bypassing the valve on the dryer by using a paper clip to see if it is low on freon, doesn't work. Have one hot wire at the compessor but nothing works.
Air Conditioning on 2000 GMC 2500 Pickup
Have a shop check for low freon in the system because the pressure switch won't power up the clutch until the proper amount of freon is in the system and you can check AC service prices here http://repairpal.com/estimator?car_type_id=5411 or locate a repair shop here http://repairpal.com/directory?address=64834&car_brand_names=GMC
ck your ground some times the wire will beak in side the inslution ck power at compressor and use the test light to ck true ground by hooking test light to the pos.side of batt.if u do not have a true ground wire the comp.to a groung right their ck power by hooking test light to groung and probe the power wire to the comp dark coler should be ground light colors power