I read all of W220 owners start here on ac/heater. There were some similar problems but mine is somewhat different. Driving around town ac is not a problem air temp is very cool and air flow is plenty esp on Max. I just took a 2.5 hour high speed (on Fl. turnpike ) drive on very hot sunny day (97 Outside). Ac was fine for about an hour then air temp warmed up (was not near as cool as when we started) and air flow cut way down, even on max, and temp set to 65 for the next 1.5 hour. Did the same exact thing on return trip a few days later. Does anyone still think it would be the Sun sensor on the hood or another one inside the car. Car is a 2000 S500. Any help appreciated.

Have not done the test , holding in rest button yet. Read not many actually showed bad anyway.

 

Have you checked your gas levels. You could be icing up the evaporator.

 

tower, Thanks for the reply, i will get that checked.