How do I fix my 2009 CLS550 when after driving for 20 minutes the Rear A.C. starts blowing out HOT air, while my front A.C. blows cold air? The temperature is set to the lowest setting. Does anyone know how I can to fix this problem?

 

Need to replace valve, part # 2118320584 see attachments here: https://mbworld.org/forums/cls-coupe...ml#post7357984

 

Got it thank you very much!