Car Window Jam? Here’s What to Do
A car window jam isn’t the end of the world.
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Whether it’s to let heat out of the car, enjoy a little breeze on the road, or to grab a cup of joe on the go, your power windows likely get a lot of use, particularly the driver’s side window. At first glance, your power windows might seem like just another convenience, but how inconvenient when they suddenly stop working.
Fortunately, you don’t have to be an automotive wizard to determine the problem with your car window jam. After discussing how the typical power window system works – manual car windows are very similar – we’ll look at a few common problems.
How a Car Window Works
The typical car window has three main components: glass, regulator, and track. Power windows have additional parts, such as the power window motor and power window switch. Car Window Glass is straightforward, a curved and shaped piece of tempered glass, offering visibility and protection from the elements.
The car window glass is contained by the Window Track, which restricts its movement to one dimension, up and down. On frameless windows, the window track is hidden inside the door, while framed window tracks continue up through the frame. For sealing against wind and water, the metal window track is lined with a rubber seal.
The Window Regulator can vary in design, such as cables or swing-arms, but its singular function is to raise and lower the glass without tilting it. Manual windows use a hand crank directly on the window regulator, while power windows use an electric motor.
The Power Window Switch gets power from the vehicle electrical system, activating on demand to raise or lower the windows. These circuits include circuit protection, such as automotive fuses or circuit breakers. More sophisticated power window systems might include pinch protection and auto-up or auto-down functions.
How Car Windows Fail
If there’s a failure in any of these parts, you can get a car window jam, and the window won’t move. A non-functional car window might be inconvenient or uncomfortable. If the window is stuck open, rain could cause short circuits, corrosion, or mold and mildew. Still, if you have a car window jam, don’t panic. Check these main failure areas:
Window track problems are usually related to the rubber liner. Look at the top of the window frame and along the track to see if the rubber is pulling away from the frame or is deformed. If so, the window glass won’t move through that part very easily or might even skip out of the track. Spray inside and outside the rubber track liner with light silicone spray to free it up. Then, pull the track out and reinsert it, using the power window to pull it back into the lower channel.
The window regulator gets a lot of abuse but is built for it. Of course, cables, rollers, and sliders can wear out, and arms can break. If this happens, replacing the window regulator will require opening the door panel, which you’ll want to get a repair manual for or seek a professional. Power windows with pinch protection need to be initialized, which might be required before or after installation.
Some damage might be caused by operator error, such as trying to pull up the glass manually or lower the window when it’s ice-bound – the glass pulls out of the holders. If this is the case, you can usually glue the retainers back onto the glass with heavy two-part epoxy, like J-B Weld or PC-7. You must open the door panel to access the window regulator, though, and wait a sufficient amount of time for the epoxy to “set” before installation.
Common Power Window Faults
You can still find manual windows on some economy cars, especially for the rear doors, but the de facto standard across the automotive spectrum is power windows. In addition to the previously-mentioned car window problems, power windows add several other fault points which might appear as a power window jam. An electrical wiring diagram and digital multimeter are indispensable in resolving electrical problems.
In older vehicles, the most common failure is usually to be found in the driver’s door sub-harness, where the wire harness crosses from the body to the door. Because the driver’s door is the most opened and closed, the wires flex until they eventually break. This might knock out all the power windows or any one of them, and it might do so intermittently until the break is clean. The best way to fix breaks here is to run new wires through the boot, making the repair inside the door and inside the vehicle instead of in the flexing harness section.
Also, in older vehicles, because the driver’s window is most likely to be opened, the driver power window motor is prone to failure. Whacking the door or the motor itself might “wake it up” for one more chance to close it. Depending on the vehicle, you might be able to buy only the power window motor, which is held to the power window regulator with a few screws. Either way, you’ll have to open the door panel to access it. As mentioned, some power windows with pinch protection are “initialized” by following a specific pre-installation procedure, matching the motor to the regulator.
Another common power window fault is the power window switch. If you remove it, you’ll likely notice it isn’t simply a switch, but contains complicated circuitry to manage the power windows, even more if you have remote power windows. Because it’s technically “inside” the vehicle, it doesn’t get as much waterproofing, if any, as exterior electronic components. Still, because it’s close to the window, it can be short-circuited by water if the window is open or if there is a leak. Power window switches in the center console are prone to circuit problems caused by spilled drinks. If everything else checks out, including fuses, relays, breakers, wiring, and motor, the power window switch may have to be replaced.