heater motor control

[celt47]

I have a 1994 325I with a very strange problem. The heater/AC fan control will work fine on all speeds and then after I turn the car off it doesn't work at all. It is like there is no power to the system. Now things get strange. With the ignition on and the fan control set to run, I shut the passenger-side front door hard and the fan motor begins to work. I have checked the resistor pack, the blower motor, the control switch and all conections. Is there something I am missing?

[dblmikeusa1]

Check for any chaffing or broken electrical wires. Something may be grounding the system fromthat area. I had something similar to that problem with a radio. when I would press my clutch pedal,a wire had fallen and became worn. It eventually would ground itself out on the pedal itself. Some two weeks of complaing only took a small repair on the wire and everything was good. Remember it is always the easiest things you should check first.

[celt47]

FYI For all E36 owners:

As it turns out, the problem with the heat/air condition fan was the motor brushes. They were shot and the "pigtail" or wire from one of them was touching a portion of the rotor or windings. I had to replace the motor and fan assembly with a new aftermarket unit because the assembly is nearly impossible to repair. Additionally, you really have to compress the fans down to get them back in.

A neat trick I discovered when reattaching the four air gate clips; was to attach a piece of double sided foam tape to the each clip. This gave you something to hold onto and helped to recover them if they slipped or were are dropped.