3 Series Sedan
- Make
- BMW
- Segment
- Sedan
It may not leave you stranded on the side of the road, but a malfunctioning car window that won't roll up (or down) can be a major nuisance. A window that's stuck open is a security risk, and it can be dangerous if you're far from shelter in frigid weather. Fortunately, it's possible to fix this issue yourself, depending on what the problem is. If the problem is as simple as a blown fuse, the fix is not only easy but cheap. However, a lot more goes into making windows work than a fuse. Our focus will be on electrically operated car windows, as these are standard in almost every single modern car sold in the USA today.
How Do Power Windows Work?
Getting a basic understanding of how power-operated windows work can show us all the parts that could fail. A basic power window system includes a switch, the battery, a motor, and gears.
Each power window switch receives a battery voltage signal, sending the relevant motor a battery voltage signal and a ground. When the motor spins, the window opens. Closing the window causes the motor to spin in the other direction. More modern cars feature quieter, more durable gear reduction type motors.
Another important component is the window regulator, which is made up of various tracks, sprockets, cables, and rollers, and plays the role of supporting the glass. There are different regulators, including a more modern high-tension cable one with a steel cable, mounting bracket for the motor, a single track, and a reel that the cable is wound around.
Instead of a more basic power-window circuit, the switches can be linked to one or several electronic modules. This is more likely the case on a driver's door panel with multiple controls, including those for mirrors, locks, or seats.
What Causes Car Windows To Get Stuck?
There are many potential reasons for a car window that gets stuck. These include:
- Blown fuses
- Malfunctioning window motors
- Accidentally activated child safety locks
- Window switch voltage issues
- Accumulation of ice, snow, or other debris in the window slot
- Accident damage to the window area
- Brittle, poorly greased window bushings
A blown fuse is likelier if either all the windows or a pair of them aren't working. If the affected window goes down but not up, a bad window switch is probably the culprit, but if the window can't go up or down at all, the problem points to a faulty motor.
Fixing A Car Window That Won’t Roll Up Or Down
You'll want to start by ruling out some obvious causes. Through a process of elimination, we'll work towards more complex issues that may require you to visit a shop.
Check The Window Safety Lock
This is the simplest fix, mostly because it isn't a fix at all. It's possible that you inadvertently activated the child safety lock switch, usually found on the driver's door, which has prevented a window from being able to open. This switch can usually be identified by a symbol of a crossed-out window on it.
Realigning Window Glass
If the window glass has become dislodged from the tracks in the door panel, or if the glass is tilted, slamming the door is another potential fix. This could move the glass back into the desired position and get your window working again.
You can try this by doing the following:
- Switch your car on
- Press and hold the window switch, depending on whether you want to move the glass up or down
- While continuing to press and hold the switch, sit in the car and slam the door shut. Continue opening and closing the door (while holding the switch) to see if this fixes the issue.
Repairing A Blown Fuse
Your car's manual will be able to tell you where the fuse box is located, but it's normally in the glove box, below the dashboard, or tucked away in the engine compartment. A numbered diagram should tell you which fuse is for the power window circuit, and you may need to consult the manual for this, too.
A blown fuse can sometimes be identified by having a brownish color. You may also notice wiring that's disrupted. Long-nose pliers or a fuse puller can be used to remove the faulty fuse. After that, you'll need to replace it with a new fuse with the same amperage. It's important not to exceed the amperage of the original fuse, as this could be a fire risk.
If the window or windows work after this, you've solved the problem, but if the fuse blows again, something else could be affecting the car's circuitry.
Replacing A Faulty Power Window Switch
You should see either a change in your car's voltmeter (if it has one) or a slight dimming of the lights when you press the window switch. If you don't, the switch itself could be the issue. Since window switches are used frequently, they're susceptible to wear over time.
Replacing the power window switch will involve a fair amount of work, as you need to remove the window switch panel. This may be more difficult on your particular car, and you also risk damaging the surrounding trim if you aren't careful.
After the switch panel is removed, you'll need to disconnect the power outlet, remove the rockers while remembering the disconnecting sequence, and then replace the switch with a new one.
We recommend this step only after checking the fuse box. Better yet, it may be best to leave this job to a professional.
Replacing A Faulty Window Motor
Once again, a voltmeter and the slight flickering of vehicle lighting can indicate if there is a problem. With the car switched off but the ignition turned to the accessory position, you should see a slight change in the voltmeter and lighting when engaging the affected window switch. If you do, and the window still isn't going up or down (or makes a grinding noise), your motor could be the issue. A window that rolls down slowly or needs multiple presses of the switch could indicate that your motor is on its last legs.
As with replacing a window switch, replacing a window motor requires a few tools and care not to damage anything. You will have to remove the entire inner door panel, so we recommend getting help from a shop close to home.
This process will include:
- Removing the inside door panel
- Disconnecting the electrical connection
- Disconnecting the window from the motor
- Removing the motor and/or window regulator
This task becomes a two-man job when removing the window mounting bolts, as someone else will have to support the glass to prevent it from falling and potentially breaking.
Can I Raise A Faulty Power-Operated Window Manually?
If you can't get to a workshop immediately, you can try temporarily raising the glass manually. At the very least, your car will be secure and your interior kept dry until you have time for a more permanent fix. You'll need at least some of the glass to be visible for this to work. If it is, try the following:
- Switch your ignition to the accessory position, or switch on the car normally
- Open the affected door and place each hand as flatly as possible on either side of the glass
- While doing this, get someone else to engage the relevant window switch as if they were raising the window automatically
- Apply pressure from both hands on the glass, while also trying to raise the glass
- If the glass starts to move, take care not to get your fingers caught at the top
To keep the window glass from falling, you can get a plastic or rubber wedge from an auto parts store to jam between the glass and door edge. In some cases, you can also use tape to stick the window to the door frame, but don't use so much that it obscures your visibility.
For glass that's completely stuck inside the door, you can get a temporary car window kit with a plastic sheet that can be cut for your car's specific window opening. Along with special tape, this can be used to keep the interior protected until your window can be fixed.
What About Manual Car Windows?
With no motor or electronics, manual windows are far more basic than power ones. An issue with the regulator or stripped gears with the crank are pretty much the only problems you could face with this kind of window. In general, it will be cheaper to replace parts for a manual window. On the downside, it's not as simple to get a stuck manual window back up, as you may break the regulator.
If the window crank grinds or freewheels when operating it, the teeth inside the crank may be stripped. If the issue isn't the crank, you will need to go through the process of removing the door panel and inspecting the regulator.
The brilliant video below is a great way to understand how a basic window mechanism works.
How Much Does It Cost To Fix A Car Window Mechanism?
A new fuse can cost under $20, which will be one of the cheapest ways to remedy this issue. However, anything that requires removing the door panel will require substantially more labor, while replacing the motor or power window regulator will drive up those numbers even more. These are a few average prices from RepairPal.
Part | Average Cost |
---|---|
Fuse | $20 |
Window Regulator Motor Replacement | $305 - $410 |
Window Switch Replacement | $308 - $353 |
These costs will vary depending on the make and model of your car. For instance, a window switch replacement can cost over $600 on a BMW 3 Series, much higher than the average cost mentioned above.