my chevy uplander 07 has this problem: I will get the message ac shut of to protect engine, ac wont blow cold air and radiator fan will run all the time, engine is not hot and temp gauge will be in cold as if the car was turned off,I changed thermostat twice, and the problem disappeared for 4-5 days and everything went back to normal (temp gauge working fine, ac cold...), but now is doing the same. Any Ideas?