I also have a problem with my climate control. At first, it would blow hot air every so often when the AC was on. It would stop after maybe 45 seconds and blow cold air again.
Now the blower has ceased to blow, except unpredictably every several days or so. Hot air comes out of the side vents, not the center vent. When I am traveling over 30 mph, the defroster emits warm air.
This is on a 1990 300D 2.5 Turbo. Another problem is that the power window switch on the console for the LR window does not work. The window will come down with the switch on the LR door.
How do I check the blower circuitry and fix it/replace it and how do I remove the power window switch? Is this info available in the latest Haynes Manual?