Troubleshooting and Repairing a Broken Electric Vehicle Window Regulator

By Isabella Storyclaire

last updated September 17, 2024

Contributions sourced from

5 Reasons Why Your Power Windows May Not Be Working

Once upon a time, all car windows needed to be rolled down manually, but thats not the case today. Most modern vehicles are now equipped with power windows. While this feature ensures you get fresh air faster, it can also mean problems when something malfunctions. What are some of the main reasons your power windows are not working?

In most cases, something electronic has failed, but dont underestimate the power of the weather either. In this guide, I touch on the top reasons the power windows arent working.

5 Causes of Power Window Failure

The most common reason why power windows are not working is due to a broken window regulator or a broken window motor. It can also be caused by faulty wirings between your cars body and the door, which is quite a common place for them to break.

Here is a more detailed list of the most common causes of power window failure:

1. Broken Regulator

To move each power window up and down, a regulator is needed. With every door that has a power window, there is a regulator in place.

When this window regulator goes bad, nothing will happen when the up or down button is pushed. The only way to fix the problem is to replace the regulator.

The regulator is made of steel cables which can start to rust and fail over time. Sometimes, when these regulator cables fail, the window will be stuck at the bottom of the door.

2. Broken Window Motor

In addition to the regulator, each power window also comes with a motor that powers the operation. At the end of the motor is a gear that connects to the window regulator for seamless movement.

Before the regulator is activated, you push the power button on the door to activate the motor. This motor is responsible for putting the regulator into motion. If the motor goes bad, theres no power to make everything operate.

3. Bad Weather

When ice and snow hit, you can guarantee that the window function might suffer. The cold weather brutally affects the functionality of power windows, mainly because the glass starts to stick to the frame.

In some cases, the regulator might be strong enough to move the window from the frame, even if it is frozen. However, trying to force the window to move in cold weather is going to cause the regulator to wear out, as it isnt meant for extreme conditions. It would be best if you removed the snow and ice first and allowed the windows to warm up before trying to operate them.

4. Malfunctioning Power Window Switch

When you push the window switch on your door, you expect that the window will just work. However, this switch can also wear out over time. With every push, the switch wears just a bit, reducing its life by one more operation.

If you are rough with the switch or use it often, you might notice that it wears out faster than you expected. Thankfully, power window switches arent expensive to replace and are one of the easier problems to solve.

5. Electrical Wiring Problems

Connecting the window switch to the motor are several wires. While this is one of the least common reasons for power window failure, you cant overlook the possibility that the wiring is damaged or broken.

In some cases, it might have happened when you were repairing another part of the power window. You might have accidentally damaged a wire during the replacement. However, you dont need to examine the wires until the more common possibilities are looked at first.

Your car often also has control modules for the power windows which can fail, depending on the car model. In some cases, there are also fuses to the power windows which can be good to check before you start to replace any parts.

You should also check the wirings between the cars body and the door, a common place where the wirings will break.

How to Troubleshoot Power Windows That Dont Work

1. Access the Window

To properly check the system, you must have access to all of the window components. This requires you to remove the trim panel on the interior of the door holding the bad window.

Some panels are held in place by snap fasteners and others use screws or bolts. Use caution when removing the panel, ensuring you dont break any delicate parts.

2. Use a Test Light

Plug your test light in place of the motor. If the connector contains more than two wires, you might be looking at a position sensor as well. In this case, its best to review the schematic to determine which wires are supplying power and which is the ground before you hook up the test light.

Once you have the test light connected, turn your key to the ON position. Try to operate the switch in both directions. If you get a bright light, the circuit to the motor is functional. If the light only comes on in one direction, you might have a bad switch.

3. Check the Motor

Connect the motor and test again. If you have circuit operation to the motor, but the motor is failing to work, there is something worn internally.

In some cases, you can lightly tap on the motor while you hold the switch in position to get it operating. If that doesnt work, replacement is necessary.

4. Inspect the Regulator

Mechanical regulators can break the guide wheels that allow them to move on the tracks. With broken guide wheels, the glass can bind up.

Cable regulators are easier to troubleshoot because you will see detached or kinked cables. If the motor is working and you dont spot regulator damage, you could also check the gearing of the regulator. Some windows use plastic for the gearing, which easily strips or breaks.

5. Inspect the Rubber

With everything else working as it should, you could also check the rubber. While the auto glass is disconnected from the regulator, try to move the window in its channel.

If you can move it smoothly in your hands without binding, theres nothing wrong. However, if it binds, the rubber channel might be worn or contaminated with dirt. Clean the area and lubricate the rubber to see if that resolves the problem.

Repair Cost to Fix the Power Windows

The best-case scenario is that you need a power window switch, which is the least expensive repair. However, if you are looking at a car window regulator replacement, the cost could be between $250 and $400, with labor making up $70 to $100 and the parts costing $180 to $300.

If you need the power window motor replaced, your cost will be around $100 to $150 for labor and the part adds $70 to $200. Combined, this gives you a total of $170 to $350 for the entire job, unless you can replace the motor yourself.

If you are lucky, the issue is just a broken fuse or a failed relay which will often be very cheap to replace and fix.

Categories: Electric, Troubleshooting

Power window regulator, window motor: problems, testing, replacement

Updated: August 14, 2021

Ford cable-type window regulator

The mechanism that moves the window up and down is called the

window regulator

. In some cars, the

window motor

comes with the window regulator as one unit (see the photo); in others, the window motor can be replaced separately.

There are two basic types of window regulators: the cable type (the top image) and the gear-drive type (the image below).

There is one window regulator in each door. A window regulator doesn't need any maintenance or adjustment. If it fails, the failed part or the whole unit must be replaced.

Window regulator problems

A broken window regulator cable can cause the window to jam or fall down inside the door. See this

example

, where the cable broke and the power window stopped working.

Worn out cable guides or a frayed window regulator cable can cause abnormal noises when the window is moving. For the same reason, the window may not go up or down all the way.

In cold temperatures, the window may freeze in closed position. When the window switch is operated down, the window can separate from the window regulator.

Toyota gear-drive-type window regulator

If this happens, in some cars, the window can be re-secured without replacing parts, in others the window regulator might need to be replaced.

A car is considered unsafe when power windows don't function properly. Several car manufacturers issued recalls to address concerns with a power window mechanism. You can check if a car has any outstanding recalls at the

NHTSA website

Symptoms of a bad window regulator:

- the window falls down inside the door

- abnormal noise when a window is moving up or down

- the window rises slow, jams or doesn't close fully

- the window slides up or down crooked

- when the window switch is pressed, the window motor runs but the window doesn't move.

Power window troubleshooting:

As working power windows are important for your safety, we recommend visiting a dealer or a reputable shop if you have a problem. Dealers also have a scan tool that can test the window switch, motor and other electrical components. If you want to know more, here's a few tips on how mechanics troubleshoot power window problems, follow the links:

What does describe the problem best when the window switch is operated:

Window motor runs but the window jams or doesn't move at allPower window goes down, but not up, the motor is not running when the switch is in "UP" position.The window goes down OK, but is slow going upThe window goes up but then backs downWhen the window switch is pressed, nothing happensWindow motor runs but the window jams or doesn't move:

In this case, we know that the window switch, the wiring and the window motor work. That means the problem is with the window regulator. We would still have to take the door cover off and check if the window motor gear is not damaged and if the glass is still connected to the regulator.

Power window goes down, but not up, the motor is not running when the switch is in "UP" position:

We know the motor works. The main switch on the driver's door is common to go bad. We can try wiggling the switch in "UP" position and if it makes the window motor run, then we know the switch is bad. If it doesn't, then we would have to follow the electrical diagram and check the power window circuit.

The window goes down OK, but is slow going up:

We would have to check the window run channels and the window regulator mechanism. Sometimes window run channels wear out or shift out of place. The window run channel is not expensive and is not very difficult to replace. Often lubricating window channels with a special silicone lubricant helps. The sliding parts of the window regulator may also need to be greased. If lubrication doesn't help, the window regulator may need to be replaced.

The window goes up but then backs down:

In many cars the power window have the anti-pinch function that reverses the window from going up when an object is pinched by the window. Sometimes, after the window motor or regulator has been replaced or the power has been disconnected, the initial power window settings must be relearned for anti-pinch function to work properly. The re-learn procedure is different for different cars. Try googling

'power window re-learn procedure Make Model Year'

, there are plenty of YouTube videos how to do it.

Nothing happens when the window switch is pressed:

If the window motor doesn't operate at all, the first thing to check is the fuses. See:

how to check fuses

. If the fuses are OK, the next step is to check the voltage at the motor and test the motor itself. It's not uncommon for a window motor to go bad. See how to test a window motor below.

Window regulator replacement

Replacing the window regulator is not very expensive ($50-140 labor, $40-$180 part) and aftermarket parts are often available. Some dealers have parts in stock. As a DIY project, the window regulator replacement rates from 5 to 7 on the scale from 1 to 10, with 10 being the most difficult. You might need to enlist one of your friends to help, as the glass needs to be held in the top position while the window regulator is replaced.

It's also very common for door cover clips to break whenever the door cover (panel) is removed. You may want to order a couple of new clips. Typically, there are 8-10 clips holding the door cover.

Window regulator AUTO-UP function reset

In many cars, the power window must be reset after the window regulator or window motor is replaced or the AUTO-UP function will not work. You can google the specific reset procedure or check the owner's manual for your car. For example, the Quick Tips brochure for the 2007 Mazda 6 describes the procedure:

With the ignition switch " width="50"ON", press switch and fully open the power window. Next, pull up switch to fully close power window and continue holding switch for about 2 seconds after window is fully closed. Repeat the same steps for the front passenger window from the passenger door switch.

How the window motor is tested

In this car, the window motor in the right front door stopped working. Pressing the window switch up or down does nothing, however all other windows work. We checked the service manual that says to remove the interior door cover and check for battery voltage at the window motor connector.

The manual says to operate the window switch and check for the voltage at the connector. When the window switch is pressed "Down" the multimeter measures 12 Volts, so we know there is power at the window motor switch.

When the window switch is pressed "Up" the multimeter shows -12 Volts, because the polarity changes when the window switch is moved from "Down" to "Up" position.

Next, the service manual asks: does the motor operate by connecting the battery voltage directly to the motor? We did it and nothing happens, the window motor is bad and must be replaced.

The window motor comes together with the window regulator as an assembly for this car. The new part was less than $100 and it took around one hour to replace.