Hi all - Just reporting back to this thread for the archive. The AC problem finally revealed itself in the fullest as I was pulling our camper on a 4-hour trip in WI. The clutch locked up solid and the AC belt began its loud, smelly decomposition. Nothing like being on the road pulling a load to completely lose AC in 90+ humid weather, also to wonder if something more was going on with the noise and burn smell. After pulling over and lifting the hood for a visual inspection, decided to continue on. Thankfully, it was contained to AC system. This time, we let the trusted GMC dealer replace the compressor/clutch, tensioner and belt. It's blowing cold and running great now. Speaking of blowing, it was $145 diagnostic + $1,500 parts and labor -- all OEM, but it's fixed. I also had them fulfill a recall claim on the airbag replacement. Related/unrelated, my airbag light had come on a few weeks ago, and it coded as the Left Front Impact Sensor, of which they quoted $530. While I paid another $145 diagnostic fee that was part of the quote (didn't have a scanner that reader SRS) to learn that, I made myself feel better by buying the sensor for $70 from Autozone and installed it myself. Light off! Regarding the AC clutch, I'm thinking it must have begun failing when symptoms first came about. As always, I appreciate all your thoughts and perspectives when trouble shooting. THANK YOU!