Lying at the heart of the Volkswagen Jetta power window system, the window regulator is a series of linkages that regulates or controls the rising and falling movement of the window pane in the driver's and passenger's side windows of the Jetta. Volkswagen has designed the window regulator to last years of use, but various factors such as stress and weather conditions will eventually cause the window regulator to wear out. In addition, damage from collisions can also cause the window regulator to malfunction. These signs of wear or damage vary widely, though the most common problems with the Volkswagen Jetta regulator include:
If the window pane does not completely close or open, there might be something that's obstructing the movement of the window regulator linkages. This problem often occurs during the winter months, as ice can build up and freeze the linkages of the regulator. In such cases the interior panel of the affected door will have to be removed and the obstruction taken out. In addition, there have also been instances where the joints in the window regulator have rusted, causing the window pane not to close or open fully. Lubricating or replacing the corroded joints often solves this problem.
On the other hand, if the window pane is refusing to move even when the power window switch is turned on, the problem may be with a loose or broken window regulator cable or linkage or a burned-out window motor. If the power window switch is turned on but there's no sound coming from the motor, the window motor is likely to have burned out and needs replacing. On the other hand, if the switch is on, the motor is humming but the window pane isn't moving, the window regulator is likely to be the culprit. To solve this problem, the compromised cable or linkage of the window regulator must be repaired or replaced accordingly.
If the window pane moves with a screeching noise, the joints may have rusted and causing friction in between the two linkages. Cleaning the rusted joints and applying lithium grease on the affected linkages normally fixed this, although make sure to turn off the engine and detach the battery cables before doing so to prevent an electric shock.