991 HVAC Mystery: Blower Issues & Warning Light Help?

Hey there, I had a similar issue with my 2011 Porsche Cayman S last year. The symptoms were nearly identical, inconsistent AC/heat performance and blower issues. Initially thought it was the solar sensor too, but it turned out to be a defective wiring harness behind the dashboard. Took it to my trusted independent Porsche specialist after having the same dealership concerns. They found several worn-out wires in the harness that were causing electrical gremlins in the HVAC system. It was actually a serious issue that needed immediate attention because the faulty wiring could potentially cause more electrical problems or even short circuits. The fix required removing part of the dashboard to access and replace the wiring harness. It wasn't a quick job, but it solved all the HVAC issues and the warning light. No problems since then. Best of luck!

Hey, thanks for sharing your experience! This is really helpful since I'm dealing with almost the exact same symptoms. By the way, do you remember roughly how much the wiring harness repair set you back? Also, just curious, have you had any other electrical quirks pop up since getting it fixed? Cheers!

Hey again! Yeah, of course I can help with those details! After seeing my mechanic, they found both the solar sensor fault and the wiring harness issues, got them both sorted out. The wiring harness repair came to 155€, which honestly wasn't as bad as I initially feared. And nope, absolutely zero electrical gremlins since the fix! The car's been running like a dream, AC, heating, and blower all working perfectly. Really glad I got it taken care of when I did. Sometimes these electrical issues can snowball if you leave them too long, you know? My advice would be to get it checked out sooner rather than later. These Porsches are amazing machines, but when they need attention, it's best not to wait around. Let me know how you get on with yours! Cheers!

Thanks so much for all the info! I actually just got back from the mechanic today. You were spot on about getting it checked quickly! Turns out my issue was pretty similar, faulty wiring and a blown fuse behind the dash. The mechanic I found specializes in German cars, and they did a fantastic job. Total bill came to about 200€, which included a thorough diagnostic check. They also spotted and fixed a small coolant leak while they were at it. The car's running perfectly now, AC's blasting cold air again, and that annoying warning light is finally gone. Such a relief! Definitely dodged a bullet by not letting it get worse. Really appreciate everyone's help and advice on this. Sometimes these fancy cars can be a bit tricky, but finding the right mechanic makes all the difference. Take care!