1980 450SL with digital heater control valve installed to replace original equipment vac/elec junk one! Any button pressed except defrost, quits when power applied to engine. Have to press def then the button for whatever function desired to get it to come on.
A/C & heater work but will stop when accelerating. If leaving from a stopped position, seems to quit around 2500 RPM. If driving at speed, seems to quit as soon as acceleration begins (i.e. passing another vehicle, going up a grade, etc). Was the same with the original vac/electric valve. Sometimes it will return on its own but to get to come back, you have to press the defroster button then the button for the desired flow (i.e. auto hi, auto lo, etc).
A/C & heater work but will stop when accelerating. If leaving from a stopped position, seems to quit around 2500 RPM. If driving at speed, seems to quit as soon as acceleration begins (i.e. passing another vehicle, going up a grade, etc). Was the same with the original vac/electric valve. Sometimes it will return on its own but to get to come back, you have to press the defroster button then the button for the desired flow (i.e. auto hi, auto lo, etc).
Feb 21, 2012 at 2:41 AM
