The window regulator on your BMW is a critical part of your car's electronically-controlled window assembly. The window itself is moved by a single cable that drags the window up and down the window rails installed inside the door frame. Depending on the symptoms that your window shows, any issues you might be encountering might not be caused by the window regulator per se. Fortunately, determining whether or not the regulator is the source of your window problems is an easy procedure that will take only a few minutes of your time.
Get into your BMW and turn the ignition key so that the car's engine is fully on or so that the key is in the "Accessory" position.
Using the window controls mounted on your door or mounted in the center of the car, attempt to open and close all of your car's windows. Listen for any strange noises that may predicate the window issues.
Your window regulator is broken if you have heard a mechanical crackling noise while trying to open and close the window.
Determine if the window is completely jammed or not following the emission of the noise in Step 3. Should the window be jammed following the mechanical noise, your window regulator is likely broken and will need replacement.
