I have to share this because honestly I have been dealing with a nightmare AC situation for almost four months and I am so relieved that it is finally over. I drive a 2017 Mercedes S Class and the AC started acting strange last winter, nothing too bad at first but then gradually it got worse. The passenger side would blow cold but the driver side would blow warm air. Then after a while, the rear vents stopped working completely. I took my car to three different garages and each one gave me a different story. The first place said I needed a complete new compressor for almost 6000 dirhams. The second place said the evaporator was leaking and wanted to remove the whole dashboard. The third place told me it might be a software issue and charged me 800 dirhams just to run diagnostics and then said they could not figure it out. I was honestly losing hope and started thinking maybe I should just sell the car. But then a friend who owns an E Class told me about his experience and suggested I look for a specialist that deals specifically with Mercedes climate control systems because these cars have multiple sensors, stepper motors, and a complex refrigerant distribution system that most general garages do not understand. I did some research online and found a Mercedes AC Certified Repair Workshop that had really detailed reviews from other Mercedes owners. I decided to give them a chance and honestly it was the best decision I have made. They diagnosed the problem within an hour and told me that the issue was a faulty duo valve that controls refrigerant flow between the left and right sides, plus one of the stepper motors for the temperature blend door was stuck. They did not try to sell me anything unnecessary. They replaced only the faulty parts, did a full system evacuation and recharge with the correct Mercedes specification refrigerant and oil, and also ran a calibration on all the HVAC actuators through their diagnostic computer. The total cost was less than half of what the first garage quoted me just for a compressor. Now my AC is blowing ice cold on all sides and the rear works perfectly again. I am so happy that I did not give up on the car. If you own a Mercedes and are having AC issues, my advice is to avoid general garages and take it somewhere that has the proper training and equipment for these cars. Do not let anyone just start replacing expensive parts randomly. A proper diagnosis makes all the difference. I am just glad I can finally drive in comfort again without showing up to work with my shirt soaked in sweat. Anyway, just wanted to share my happy ending in case anyone else is going through the same frustration.