a/c clicking

I recently bought a 2002 Envoy and since I bought it I have noticed a terrible clicking sound, mostly when it is first cranked in the morning, coming from in the dash. I think it is the a/c because it doesn't cool off as long as the car is idling. I have to drive a couple of miles before it will cool... Anyone had this problem?

Also, we had our first cool spell and the heater doesn't work very well on the driver's side unless you turn the temp up on the passenger side. It's crazy... Is there some switch or regulator that controls this?

Hi LSU fan, I also have an 02 Envoy. I had that problem 2-3 months ago. I noticed that it occurred when I started the car and also when I switched the AC air vent controls from defrost to panel. The dealer said this was a problem they had with Cadillacs. Its some sort of module that controls the air flow. Estimated $500 repair job.