This does not mean just leave your AC on all the time. Seems like the obvious but there are reasons for this. First change the sensor to be sure of the readings you are receiving. Are you overheating in that you have steam coming from under the hood gurgling sounds, coolant loss or is it that the temp gauge is reading high. Back to point, leaving the AC on at start up will send irregular voltage charge to different components of the system eventual causing a problem somewhere, a very comon spot on these cars (especealy the ohv) is the blower motor resistor, you most likly have a problem here if not all the fan speeds for the AC/heat work. This is a little off topic but I wanted to explain why.