BMW E36 power windows and sunroof not working
Why do the E36 power windows and sunroof not work or work sluggishly?
A typical cause is the blue comfort relay under the steering column, whose solder joints have cracked. The relay can be re-soldered or replaced with a new one. If there are two identical blue relays, they can be swapped to see which one is faulty.
Where is the E36 door microswitch and what does it control?
The microswitch is in the door lock striker. It controls the interior light and the automatic lowering of the window when the door opens; the window drops about 2 cm and rises back when the door closes. This is normal operation. A damp or frozen switch makes the car think the door is closed.
Why does the E36 side window move only a little or not go up from the switch?
The plastic sliders of the regulator can become brittle, so the regulator rod jumps out of its cup; there are two sliders per window. Other causes are worn motor brushes or a displaced magnet disc of the position sensor. In freezing weather the glass can also freeze to the seal.