HVAC not cooling........solved!!
I did a bit of reading about the issue and then plugged in the STAR diagnostics which told me that the interior temp sensor unit was defective. This sensor is apparently part of the entire digital display/temp control/fan speed control unit on the later model W220. Anyways, I removed the entire assembly and while out I split the unit by carefully releasing the plastic snap in clips.....the front control portion of the assembly is connected to the rear by a large ribbon cable which I did not disturb. I looked at the temp sensor (thermistor) and noticed that it had a large ball of "fluff" on the sensor and some fluff in the tube the sensor fits in....removed it VERY carefully with a small screwdriver and blew it all out nice and clean. Assembled the unit and reinstalled the unit for testing.......45 degrees all day long......FIXED!!
Very happy with the results.....hope it helps someone else.....







