BMW Climate Control Dead: AC and Heat Mysteriously Fail

Had a similar issue with my 2012 BMW 3 Series diesel. Dealt with the same symptoms last month, climate control going haywire and heat barely working. Turned out it wasn't the solar sensor in my case. The technician found it was a loose connection in the HVAC control module wiring harness, plus some corroded pins in the main connector. The repair wasn't too complex, but accessing the component was tricky as they had to remove part of the dashboard. They cleaned the connector pins and secured the wiring properly. The issue hasn't returned since. This wasn't a serious mechanical problem, more of an electrical annoyance that needed proper diagnosis. Your symptoms sound identical to what I experienced, so I'd suggest getting it checked by a BMW specialist who can properly test the electrical connections before replacing any parts.

Thanks for sharing your experience! That's really helpful to know it was just a wiring issue in your case. I'm curious, do you remember the repair cost for fixing those corroded pins and connections? And has everything been working smoothly since then, or have you noticed any other quirks with the climate system?

Hey there! Just wanted to follow up on your questions. I actually had my issue resolved differently than what I initially thought. While I mentioned the corroded pins before, when I took it to the mechanic, they found it was indeed the solar sensor fault I originally suspected. The fix was pretty straightforward, just needed to repair a faulty cable connection to the sensor. Cost me 95 € and I'm happy to report everything's working perfectly now. The climate control's back to normal, no more temperature fluctuations or heating issues. What a relief! It's amazing how such a small component can cause so much trouble. If you're still having problems, I'd definitely recommend getting the solar sensor checked out. Sometimes the simplest solution is the right one! Let me know if you need any other info about my repair experience.

Thanks for the update and information! Just wanted to let you know I finally got my car looked at. Surprisingly, it turned out to be a completely different issue than both the sensor and wiring problems. The mechanic found a clogged heater core and a failing blower motor. They had to flush the entire system and replace the motor. The repair was pricier than I expected, around 400 bucks total, but at least the climate control's working perfectly now. The heat's nice and toasty, and the AC controls are responding like they should. Definitely worth every penny not to freeze during my morning drives anymore! Funny how car problems can turn out so differently than what we initially suspect. Really appreciate everyone's input on this. Think I've found a reliable mechanic now too, which is a huge bonus. They took the time to explain everything and even showed me the gunked-up parts they removed.