Mercedes R Klasse Diesel AC Compressor Failure

I am sorry to hear about the AC compressor issues in your Mercedes While I do not have experience with the Mercedes R Klasse, I encountered a similar problem with my cooling system in my older BMW 5 series a while back My AC unit issues also manifested as a complete failure, and the symptoms were quite similar – no cold air, warning lights, and error codes Have you checked the auto refrigerant levels While it is unlikely to be the sole cause of a complete compressor failure, low refrigerant can sometimes trigger similar symptoms and error messages Also, it might be worth checking the compressor relay and fuse before assuming the control unit is defective A faulty relay can prevent the compressor from engaging

Thank you for your detailed response Regarding your suggestion to check the auto refrigerant levels, compressor relay and fuse, could you elaborate on how to check these components I am not particularly experienced with automotive cooling repair, but I am willing to learn if it saves me from incurring the repair bill

Certainly While I am an enthusiast I am not a mechanic, please proceed with caution Checking the refrigerant level typically requires specialized tools and knowledge, as releasing refrigerant into the atmosphere is harmful and illegal in many places I would recommend you get a professional for this one As for the relay and fuse, the location depends on the vehicle's specific configuration Consult your owner's manual or a wiring diagram for the AC system The relay can be tested by swapping it with an identical relay from another non-critical system (e.g., the horn relay) and seeing if the AC compressor now engages A fuse can be visually inspected for a broken filament or tested with a multimeter Given the complexity and potential risks involved, especially with the potential for a defective air conditioning control unit, it would be advisable to seek a professional diagnosis from a qualified workshop They can accurately pinpoint the source of the problem and ensure the repair is done correctly and safely I hope this helps, and I hope the situation gets resolved easily for you

I appreciate your advice and second assessment I will take your suggestion to seek professional help for this issue Thank you for confirming my suspicion that AC unit issues are likely due to a defective air conditioning control unit instead of a cheaper fix I took it to the workshop, and they confirmed your suspicion that the AC compressor failed due to the defective air conditioning control unit So I had it repaired as discussed before Thanks again for the help