Q – My 944 climate control doesn’t work and I am planning to drive it this winter so it has to keep me warm. When I rotate the fan control knob, nothing happens, it just spins. When I rotate the temperature control, I get no heat. Got any hints? This is going to be my daily driver and I’ve got plans for it but I need to keep the bill at a minimum right now. Calvin

A –       It is a rare individual who plans to drive a Porsche in the winter, and I salute you, sir.   I have driven my 944 in the winter too and it is an excellent car with all season tires and about 300 pounds of sand in the rear hatch area. No problem, except for the salt! Wash the underchassis regularly. But I digress…

The problems you are having could turn out to be quite expensive. For now, I will just focus on getting heat. First of all, the climate control should fail safe in defrost mode, full heat and yours does not. Have you had any cooling system work done on it? Sometimes an air bubble will keep the coolant from flowing through the heater core.  Assuming there are no bubbles and that warm coolant is reaching the valve, to see if the heater could work, disconnect the vacuum hose to the control valve, in the engine bay at the center of the firewall. You should now get heat. The heater control valve is the same part as used on older Audi 5000’s and when vacuum is absent, it goes full open, full heat. If you still get no heat, remove and inspect the valve.   I have seen some where the lever moves but it is not connected to the flap inside the valve.

As far as the fan, sometimes the knob simply breaks free from the shaft. Pull the knob off and see if you can rotate the inner part of the fan switch shaft. If you can turn the fan on…simple, a new knob fixes it. If you only get high speed, the fan resistor might have failed. The resistor fits onto the blower box, driver’s side top and it is one of the easiest fixes for missing fan speeds.

This should get you heat and hopefully by next spring, you can take the diagnosis to the next point and get the temperature control functioning again. – MC

CategoryMasterCylinder, MC944