I had the same exact problem...
See this thread: http://www.benzworld.org/forums/w14...-500sel-evaporator-climate-control-issue.html
I replaced the duovalve and problem solved. Got the valve from S Class Eddies.
See this thread: http://www.benzworld.org/forums/w14...-500sel-evaporator-climate-control-issue.html
I replaced the duovalve and problem solved. Got the valve from S Class Eddies.