Chevrolet Repair Questions? Ask a Mechanic for Answers ASAP
Assuming that the AC is fully charged, it sounds like you might have a bad pressure switch. The pressure switch is supposed to tell the compressor when to engage as long as there is enough refrigerant pressure in the AC system.
You can test this by unplugging the pressure switch-the low side switch is located on the receiver dryer- and then jump the pins in the connector together with a jumper wire or paper clip. If the AC is set to on and the engine is running, the compressor clutch should cycle on. If it does, then the low side pressure switch is bad- or there isn't enough freon in the system.
If it ran the compressor but never got cold then I would say the issue is probably just low freon.
If you have a gauge set you could check line pressures and it would give you an idea of how much freon is in the system.
Please let me know if you need additional information.