The air conditioning has been working perfectly as long as I have owned the car -primarlily driven in Southern California. Last July (2006), on a trip to Arizona, the A/C stopped blowing cold in the 100 degree weather. A local MBZ dealer did an A/C service, but that did not correct the problem.They could not diagnose the problem and simply suggested I replace the entire system at just shy of $3,000, I declined. A few days later, the car was returned to San Diego where the A/C started blowing cold and working flawlessly. Ten months later (May 2007), returned on a trip to Arizona and the A/C stopped blowing cold again. However, upon retunrn to San Diego and 60 degree weather, the A/C has not blown cold again. I appreciate any thoughts.

 

try changing the evaporator temp sensor they've been known to cause inter. probs