1989 300E Mercedes air conditioning problem

[gary_sdg@qwestoffice.net]

What is happening is hot air coming out of driver & passenger side ports, while cold air is coming out of the center ports. Could it be vacuum check valve for climate control. Any advise would be appreciated.
Thank you

[nulu]

sounds like heater valve, mono or later duo-valve leaking , when not commanded , hot coolant maybe coming thru, to test pinch th heater valve hose and see if heat stops coming out sides , if it does , check for electrical operation , if that checks ok replace valve as rubber seal internally are probably torn

[gary_sdg@qwestoffice.net]

Thank you Nulu