Cayenne ventilation problem

[dbrich]

I recently purchased a 2003 Cayenne S. It appears I may have inherited a heating/ventilation problem. The heating/ac/ventilation fan motors work fine but no air is reaching the dashboard. All the air flows to the floor and side vents. A diagnostic check indicated that the defrost servo motor was faulty. As no air from any source reaches the dashboard under any setting of heating control (or via a/c) I assume that the upper airflow must be via a common contolled flap so I am beginning to think it might just be a sticking flap. The big problem is of course -- where is the flap, can it (or the defrost servo motor) be accessed by removing the dash undertray -- or is it a dashboard-out job ? Your thoughts are much appreciated.

 

[dbrich]

Just to let you know the defrost/demist problem has now gone away. The diagnostics had revealed a defrost servo motor fault and a sun sensor fault. I tackled the sun sensor first as it was easier to get to (still don't know where the servo motors are located). I disconnected the sensor and tried the defrost and lo and behold it worked --as did the normal demist with lots of air now reaching the dashboard vents. All the servos seemed to spring into action and there was a bit of relay chatter from beneath the dash. Playing devil's advocate I reconnected the sensor --- the chattering stopped and strange as it may seem, everything still worked ! Unless I had inadvertently disturbed a loose connection I can only assume that temporarily disconnecting the sun sensor reset the servos. Will keep you posted if fault reappears.

 

[pwebb]

Much respect, didn't even know it had a sun sensor, let alone know where to look for it!

 

[dbrich]

Thanks Peter for your comments. I got a lot of info from a cd I bought off ebay, albeit based on a Canadian model, and also from an official porsche spares site --- :- www.porsche.com/uk/accessoriesandservice/porscheservice/originalparts/originalpartscatalogue/ The website gives parts info for all models of Porsche. I've just been inspecting the battery today ----- located under the front passenger seat. What a job --- glad I'm not the fireman whose job it is to disconnect in the event of an accident !! Cheers, David R.