Hi, I had a similar problem with my 2013 Citroen C5. I would describe myself as someone with some experience with cars. When I observed the same symptoms in my car, I went straight to my garage. There they discovered that the wiring harness was faulty. The work cost me around 155 euros. Of course, it is difficult to make an exact statement from a distance, but it might be helpful to know a little more about your vehicle. How long have you had these problems and has there been any previous work on the ventilation/heating system?

(Translated from German)

Thanks for your tip. These problems occurred 2 weeks ago. Before that I had no problems with the ventilation/heating and nothing was done about it. My DS5 now has 66407 KM on it, the last service was 6 months ago. I hadn't heard anything about the wiring harness yet, but I'll take it to my garage. Maybe that's my problem too. Thank you very much!

(Translated from German)

Hey, you're welcome! Hope it helps you. Two weeks is a long time when you consider how unpleasant poor heating/cooling can be, especially now that it's getting cold. In my Citroen it was the wiring harness, but of course the problem could be elsewhere. Since your last service was 6 months ago, it certainly won't hurt to take another look at the vehicle. And who knows, maybe it really is just the solar sensor. Please keep us posted on what comes out of it, I'd be interested to know. And don't let it get you down, you can learn a lot about cars from something like this. Good luck!

(Translated from German)

Hey, thanks for the kind words! Yes, you're absolutely right, especially now in the cold season it's really unpleasant. I'll definitely pass on your recommendations to my garage and hopefully it really is just the solar sensor or the wiring harness. I'll definitely keep you posted and share what comes out of it. And you're right, you never stop learning, even with cars. Thanks for your help and advice!

(Translated from German)