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?

 

Sorry, never heard of this issue before.... I guess if you believe the battery maintainer to be the root cause of the problem you can test theory by leaving it off, or swtiching and see how long you go before another CU failure. Good Luck!

 

Why do you think it is the maintainer that is the cause of the AC issue?

 

When the car is in the garage, the battery charger is plugged in. i was told when i bought the car, to do this if the car was going to be a pleasure/weekend car. Initially, I had a Sears Diehard Battery Charger plugged in, but the charger stopped charging and the Battery would drain. That was the first replacement. After that, I bought the Porsche Dual mode charger. When the second failure occurred, the car was in the garage, plugged in, and when i started the car, battery was low. Seat heater would not turn on, and AC control unit just went blank. in both cases there was a burnt smell coming from the AC control unit. All wiring was checked and nothing is wrong except for the internal short in the unit.