Introduction:
The window regulator is mounted in the doors of the car. The mechanism ensures the correct opening and closing of the door windows.
Electric and mechanical (manual) window regulators work according to the same principle. Instead of having to turn a crank handle, the shaft of the electric motor drives the mechanism.
Below is a picture of a window regulator from a BMW 3 Series. The door trim has been removed (it is mounted with several screws and clips). The window regulator itself is almost not visible. It is mounted on the inside of the door. The window is still mounted in it as well.
There is always a cover mounted on this side of the door. This cover must prevent moisture from entering the interior. Most manufacturers use foil for this. Other manufacturers use metal plates to which the mechanism is attached. On the car in the picture above, foil has been stuck on. The sealant residue is still present here.
Types of window mechanisms:
The image on the right shows a window mechanism with a single guide rail. The window motor pulls on the cable, causing the window mount to move up or down. This type of mechanism is often used at the rear, because the door window there is often smaller (and lighter) than at the front (where a double guide rail is usually used).
Another design is a mechanism with a double guide rail. The cable runs in a cross pattern. In this way the window mounts can both move up or down at the same time. Here too, the window motor drives the cable, which moves the window mounts up or down.
The window mechanism in the image on the right does not use cables. Here the window motor drives a gear ring, which in turn moves up or down. The mechanism makes a scissor-like movement, causing the right-hand guide in the guide rail to slide to the left and right. Due to the scissor movement, the door window will move up or down.
