Got problems with the vacuum-controlled heating valve. There is no Vaccum on vacuum hose. The vacuum line to the control unit (behind the glove compartment on the right) is in measure, the air flaps also work. Except for the switch valve from fresh to circulating air.) How can I check the function of the control gates and under what conditions must the heating valve be controlled? Who can help me? Tip? Power schedule?
Edited by Otto