logan2z

I'm posting this for a friend who is having an issue related to the heating/AC system on his 993. Hopefully someone here can offer a suggestion as to what might be the source of the problem. The car in question is a UK model 1994 993 Carrera 4 Cabriolet.

Here's his description of the problem:

In warm weather when the air con is switched on, after a period of providing cool air for 10-15 minutes, the car will then cut out when coming up to a junction, and clutch is depressed but before stopping. The car will restart after switching the ignition off and back on again. In addition the heating system then pushes out hot air, even when set to the coldest setting (with the Air con off!). If the car is then left for a couple of hours to cool down the heating system will work as normal, provided the Air con is not re-engaged.
Any advise for this very hot and bothered Porsche owner?

pp000830

Sounds like you may be seeing two unrelated but concurrent issues:

• I would disconnect and clean the battery contacts and reconnect them. Then I would I first just check the engine running voltage of the vehicles overall electrical system, is it at 13.5 Volts +? I would buy a voltage meter that plugs into the cigarette lighter, an eBay item, and observes the voltage when the engine shuts down.
• Then I would run the OBD Codes as a failed HVAC actuator as part of the Climate Control system, a common issue will throw an error code. The actuators control vent temperatures and can be rebuilt by sending them out or using a kit at the kitchen table.