I have noticed that my CC does cool the car initially at start-up...but after reaching normal temp, the clicking starts up again...and even more persistent than before!! At that point, the heat is on full bore and the CC control panel will not work at all.

Checked the temp sensor vent and that is pulling sample air. Also checked the vaccuum hose, and that is fine. Plan to pull the CC pushbutton unit (is it complex??) and clean it with contact cleaner. How ironic is it that most of the summer in Chicago has been cool...but now as it is hot in September, my ac is not reliable...and I get only HEAT!

UUGGH!