I've had my 2013 Cayenne Diesel for over a year now and this is new. Both left and right sides are normally set to Auto and 72F. When I start the car, the cooling fan comes on slow and then ramps up as the vent temp cools. Works great. Lately, it can do absolutely nothing for up to 10 minutes. It's random. Sometimes it works perfectly for days. Some days, it does this delayed start every time. Today I attached a Foxwell code reader with Porsche-specific capability and it showed Compressor PWM is 0.0%, Fan voltage is 0.0, Refrigerant pressure 8.4 bar, blower outlet temps 45-48c (113-118F.) After about 10 minutes, it came back to life and I see Compressor PWM is 77.7%, Fan voltage is 6.2v (what should it be?), Refrigerant pressure 11.4, and the vent temp dropped to 11c. So, it WORKS when it decides to come on. But why the delay? Maybe a clue, but the HVAC fan is not very powerful even on max. Could the system not start if it doesn't see the blower fan running? The tester shows there is no fan voltage, so this theory doesn't hold up unless it tried and stopped before I connected.

Air Conditioning is not functioning (no blower fan, no cooling air) for first 1-10 minutes, and then works normally. Intermittently. And once it is blowing, it works fine for short or long trips. It's only on start-up that I have an issue.

 

Replaced the blower fan assembly and all is well. Easy enough; took 20 minutes.

 

@marcus550 ,
Thank you for the update.

Johnny

 

Yes. You can find easy intructions on Youtube without removing your glove box. The blower is like 75 bucks on Amazon or Ebay. It is on of the simplest reapirs you can perform on your Cayenne. Trust me I did it last summer.