How to Diagnose and Replace a BMW Window Regulator
Replacing a BMW window regulator is a moderately difficult task. If you have the rights tools and a little prior experience in car repairs, you will be able to do this job on your own. You know that you have some window repair work to be done if the window glass doesn’t go all the way down, rolls down too slowly or doesn’t roll back up. The automatic windows are powered by an electric circuit, a motor, window switches and a window regulator. If the window motor seems to be working well you will have to replace the window regulator. Due to routine wear and tear, some parts of the window regulator may break or stop working altogether. You will thus have to find a new replacement for your old window regulator. Follow these few steps to diagnose window problems and replace a window regulator.
Step 1 - Diagnosing the Problem
If the motor stops working or if there’s a short circuit in the switch panel, you will have to work on the electric system to get the window to function properly. Since the electric systems shouldn’t be tampered with if you have no experience in carrying out repairs, get it worked upon by a trained BMW automatic window repair specialist. If your car is still under warranty, you may be covered for this expense. Conversely, if the motor functions well, you need to open the door panel to start working on the window regulator.
Step 2 - Removing the Panel
In order to remove the panel that’s attached to the door, you have to gather a few tools such as a screwdriver, a socket wrench and a toolkit (if you already have one). Start off by prying open the door panel from the edges, with a screwdriver. You need to do this carefully so as to not damage the panel.
Step 3 - Removing the Window Switch Panel
If the window switch panel is built into the door panel, you will have to disconnect the electric connector after removing the entire panel. If the window switch panel is a separate component, remove it before detaching the panel and disconnect the electric connector that lies beneath this switch panel.
Step 4 - Removing Other Components
After removing the panel, you will find cables that are connected to the locking system. Detach these cables and remove the main insulation that was placed between the door and the panel.
Step 5 - Securing the Window
Instead of completely removing the window glass, you could manually bring the glass to its upright position and tape it with masking tape to hold it in place. Use the masking tape along the side of the glass and over the top of the door frame, so that it won’t slip and fall.
Step 6 - Removing the Regulator
Loosen and remove bolts and screws that hold the window regulator in place. You will also have to disconnect the wiring harness that’s connected to the motor assembly. Once this is done, you’re ready to pull out the window regulator.
Step 7 - Installing the New Regulator
After taking out the old regulator, compare your replacement window regulator to the old one and look for any differences. They should be an exact match. Now, attach the motor assembly to the new regulator and connect the previously removed wiring harness.
Step 8 - Reattaching Components
Fix the new window regulator into position and secure it firmly by tightening all the mounting bolts. After this, put back the sound insulation and the door panel. If you had removed the switch panel separately, attach the electric connector and fix the switch panel back on.
Step 9 - Testing
Once you’ve finished reattaching all components, test the window. You should be able to raise and lower it without any problems. During repairs, if you notice that the door panel has any fasteners that are damaged, replace them with new ones.
To find replacement window regulators you could contact a certified BMW parts seller or go online to find car part wholesalers. Wholesalers will sell you parts for a price much lower than the dealer’s rate.