I have had my AC control unit replaced twice since I have owned the car. I currently have 7991 miles onthe car and other than the AC control unit, never had any other issue. The first repair was done 2 years ago when the car was still under warranty. The replacement unit failed last month, and thankfully Porsche NA agreed to cover 75% of the new repair. When the car is garaged, I use a Porsche Dual-Mode Battery Charger Maintainer plugged into 12V outlet in the passenger foot well. For some reason this seems to be causing some electrical issue within the AC control unit. Any one else have a similar issue?

 

Yes, blows cold to driver, but warm to passenger
Under warranty

 

On my car, the seat heater switches stopped working, and then the AC control unit went blank. In both instances, the unit shorted out inside and there was burnt smell coming from the AC control unit. Porsche NA had the dealer make sure there was no other wiring issue with the car.