Problems with the air conditioning and heating in Mercedes A-Class model year 2012 - suspected defect in the solar sensor

Hello, I have some experience with cars and had a similar problem with my B-Class Mercedes (built in 2010, diesel). My wiring harness was defective. I paid 155 euros for the repair at my garage. To help you more precisely, could you tell me exactly which model your A-Class is and whether you noticed any additional symptoms? The repair was a bit of a hassle for me, but once the wiring harness was replaced, everything ran smoothly again.

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Great, thanks for your answer! My A-Class is the W176 model and I haven't noticed any additional symptoms so far. It's just uncomfortable in the heat and I hope it won't be too expensive. With a mileage of 53261 km, I also recently had a service and everything was fine. Is the wiring harness a common weak point?

(Translated from German)

Moin, interesting that you have no other symptoms. Normally there are other signs. In my B-Class, the wiring harness was actually a known problem. But it doesn't necessarily have to be the same for you. A defective solar sensor could indeed be the problem, but it could also be that you have run out of refrigerant or there is a blockage in the system. It would be best to have this checked by a specialist. My garage carried out an air conditioning service at the time; they extracted the old refrigerant, cleaned the system and filled it with new refrigerant. It all cost around a euro and then the air conditioning worked perfectly again. Your mileage is pretty low for the year of manufacture and I suspect that the car is still in good shape. Hopefully it's nothing serious and just a minor issue that can be fixed quickly. Please let me know what comes out of the inspection. Good luck!

(Translated from German)

Hi, thanks for your useful advice! You're right, I should perhaps have the refrigerant quantity checked. It's reassuring that it only costs about a euro. And yes, the car is in very good condition despite its age. I'll be visiting a garage in the next few days and hope it's only a minor issue. I'll let you know as soon as I know more. Thanks again for your help!

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