1982 Mercedes Benz 300td 6 cyl Two Wheel Drive Automatic 205000 miles
I am not getting any type of air flow from the heater or defrost system. When I hit a fan button or direction control, I can hear the vents engage but then no air flow in either fan position on control option. Replaced the fuse, so that is not the problem. Is there any type of relay involved with this or a clutch type mechanism?
It sounds like a heater control valve is either malfunctioned or there is no vacuum getting to it, the heater control valve is located on the right front frame horn by the radiator, if it is not there it is on the right side of the firewall, check your heater hoses going in to the interior, and the hoses that are coming out to make sure they are the same temperature if not you have no flow which would be the heater control valve.