I cleaned the temperature sensor, and checked out the HVAC myself. The system seems to respond properly to hot and cold settings of the temperataure wheel. A cool setting, activates the A/C compressor and blows cool. A hot setting blows hot. The actual issue is that once the temperature is set at say, 72 degrees F, the temperature seems to get hotter and hotter as the car is driven. Does this sound to you like the monovalve is hanging up? Thanks, Dale