Your windows, whether they are powered by hand or through an electric window motor, will not go up and down without your BMW 540i window regulator. Your 540i window regulator is a series of gears and arms located inside your door panel that makes it possible for you to raise and lower your windows. The BMW 540i window regulator also keeps your window glass firmly in place, so that it cannot be pushed down from the top edge when it is partially lowered.

This means that in addition to mechanically enabling your windows, your 540i window regulator is also an important safety feature. If your BMW 540i window regulator fails, do not be surprised if your windows drop right into the frame and refuse to come out.

A faulty 540i window regulator does not allow the necessary pressure to keep your windows up. Of course, if your BMW 540i window regulator is not working, you will want to have it repaired as soon as possible. In some cases the 540i window regulator will not work due to grime and dirt clogging the gears. You can try removing the door panel and spraying your BMW 540i window regulator with a penetrating lubricant to loosen the gears. If this does not free your stuck 540i window regulator, however, you will need to replace it completely. If you have power windows, in some cases window troubles may be the result of a burned out motor, blown fuse, or loose wiring. What happens when you press your window switch? If you don’t hear anything at all, this usually means that your window motor is not working due to burnout, a blown fuse, or faulty wiring. However, if you hear a humming or grinding noise, it likely means a problem with your BMW 540i window regulator.