Reasons Why a Power Window Won't Work

by Keith Evans

Power car windows, while a convenience standard on many modern cars, can instill panic in a car owner when they fail to operate properly. Although power windows are relatively simple mechanisms, there are three main points of failure that may cause the window to cease operation. The faulty component may be diagnosed, and even repaired, with only minimal inconvenience.


Perhaps the easiest power window fault to diagnose and repair, the fuse is the small link between the power window and the car's main electrical circuitry. If there is a power issue within the power window circuit, the fuse will blow, stopping the flow of electricity to the power windows and preventing potential damage. If the fuse blows, all power windows in the vehicle (as well as any other electric devices that share the fuse) will stop functioning altogether. If a blown fuse is suspected, the fuse can be removed from the vehicle's fuse box under the dash or hood, and replaced with a new fuse from an automotive supply store.

Electrical Problems

If one or more power windows in the vehicle completely fail, and the fuse is not blown, there may be a more complicated electrical issue. Electrical issues can be as simple as a faulty switch or as complicated as a broken wire buried deep in the car's interior, but they can usually be diagnosed with a simple 12-volt (12V) voltmeter. Car repair experts recommend starting at the fuse box and checking voltage on the wiring at various points between the fuse box and power window, though this process can be tedious, and is often delegated to qualified repair shops.


By far the most common power window mechanism, the regulator is also a very common point of failure in faulty windows. This device--which may operate on a rack, sector or cable drive principle---is a simple component that moves the window platform, stopping it at the top and bottom of its range of motion. If the regulator fails, it must be physically accessed and replaced. Although the components are relatively inexpensive, the labor and time involved in removing and reinstalling the door panel can amount to a hefty repair bill at local repair shops.


In most modern cars, power windows are surrounded by pieces of rubber that prevent weather elements from getting inside the car door or into the vehicle's interior. As vehicles age, these gaskets may break apart or become soft, causing the window to stick on its way up or down. While a sticking window may seem like a minor inconvenience, the added strain on the window's motor can cause motor, regulator and electrical problems if left unchecked. If a window goes up or down abnormally slowly, or if it sticks in places where it should move smoothly, it may be time to replace a gasket before more expensive repairs become necessary.

More Articles

article divider