Chevrolet Repair Questions? Ask a Chevy Mechanic for Answers ASAP
Have you checked trouble codes in the computer?
If the thermostat does not regulate temperature correctly, there could be a code set in the PCM. Then the PCM shuts down a/c operation and turns off the temperature gauge. Also could be a wiring issue between the temp sensor and the PCM. Reading codes will help to narrow down the problem area.