Description and testing of the electric window lift system (BMW 5 Series E28)

The power window system operates electric motors mounted in the doors that raise and lower the window glass. The system consists of control switches, motors, window lift mechanisms, and wiring. Removal of the motors and window lifts is described in Chapter Body.

Diagnostics are usually limited to simply checking the wiring and motor contacts for minor damage that can be easily repaired. Such checks include:

• Checking the power window switches for damaged wiring and loose contacts.
• Checking power window fuses and/or circuit breakers (if they exist).
• Remove the door trim panel(s) and inspect the power window motor wiring for loose connections or damage. Inspect the window mechanisms for damage that could cause the wiring to twist.