[click to enlarge]
Are you tired of having to open your door and get out at the drive-through
restaurant to retrieve your burger? Does your window constantly reverse
itself when you’re trying to raise it? Perhaps it’s time to replace or clean
your window regulator, or install a new power window motor. The difficulty
of this project varies depending upon which year car you have, but the
results are immediate and quite rewarding. Not much is better than driving
in your BMW with the sunroof open and the windows down on a nice, sunny day.
Having a broken window regulator can surely put a damper on that. Or
worse—if you own a convertible, a broken window regulator will keep you from
putting the top down.
The first step in replacing either the regulator or the power window motor
is to remove the door panel. Make sure you eliminate the power window switch
as a potential problem, however, before you start tearing into your door.
Double-check all the fuses that control the power windows, and swap out the
relays to make sure there isn’t a problem with one of them. If one window
works and the other doesn’t, chances are it’s the window motor or the window
switch. The switches themselves are often faulty, which can sometimes make
this an easy fix. Test the switch by removing it from the center console,
and swap it with one that is working. If there is any noise coming from the
door (such as clicks or whines) but the window isn’t moving, then it’s quite
obvious the motor is fine, but the regulator needs to be repaired.
For details on removing the door panel, see Project 67. When you have the
door panel removed, you can access the regulator. With your fingers clearly
out of the way, roll down the window until it’s about 75 percent of the way
down. Take a look at the white, square plastic sliders that attach the
bottom of the regulator to the window. If they are worn (and they’re almost
always worn), replace them using the procedure documented in Photo 3.
If your window doesn’t respond at all and you’ve eliminated the possibility
that it might be a broken window switch, then you’ll need to remove the
window regulator. Unfortunately, the window regulator is attached to the
door frame with rivets. You will need to drill out these rivets in order to
remove the regulator from the door. (See Photos 2 and 3 for details on
removing the regulator.)
With the regulator detached from the door frame and the window, you should
test the motor prior to disconnecting the electrical connection. With your
hands out of the way of the regulator, carefully press lightly on the window
switch and see if the regulator moves. If the window was stuck previously,
but now it moves, it means that the tracks of the regulator and the window
are sticky and need lubrication. Photo 4 and Photo 5 show the process for
greasing the regulator tracks prior to reinstallation. If the motor doesn’t
move at all, it is probably worn out (assuming you’ve checked the window
Before you reinstall the regulator, I recommend you inspect and replace the
front window channel guide too, if it’s worn. This is the channel that
guides the front of the window as it is raised and lowered by the regulator.
Also worth replacing are the window slot seals. These inner and outer window
scrapers keep water from dripping down into the recesses of the door. You
should grease each and every moving part of the regulator: the slides, the
motor, the gears, and the large-toothed section of the regulator.
Before you close everything up inside your door, it’s a wise idea to test
the proper operation of the window. Hook up the power connections to the
window motor, and try to raise and lower the window. Also verify the stop
positions of the window once you have reinstalled the regulator. There are
screws located inside the door that control these stop positions. Once
you’re satisfied everything is running smoothly, reseal the door panels and
you’re on your way again.
If you would like to see
more technical articles like this one, please continue to support Pelican
Parts with all your parts needs. If you like what you see here, then
please visit our online BMW catalog and
help support the collection and creating of new and informative technical articles like
this one. Your continued support directly
affects the expansion and existence of this site and technical articles
like this one. As always, if you have any questions or comments
about this helpful article, please drop us a line.