Signs of a bad window regulator, window run channel, replacement cost

How do power windows work in a car? The window glass slides inside the window run channel, which is a rubber part that sits within the metal frame, see the illustration.
Window regulator and window run channelWindow regulator and window run channel. 1 and 2 - window regulator clamps that hold the glass. 3 - window motor. 4 - window regulator cables. 5 - rails that window clamps slide on. Some cars have only one rail.
When you press the window switch to open the window, the electric motor operates a mechanism that is called a window regulator that moves the window glass down. When you operate the switch to close the window, it changes the polarity of the electric current and the window motor runs in the opposite direction moving the window up.

Working power windows are vital for safe driving. In many jurisdictions, power windows (if equipped) are required to be operational for a vehicle to pass a safety inspection.

Are there any signs that the window regulator is failing? Yes. For example, the window regulator cable rarely breaks in one instance. It's made of several strands of wires and as it wears out, a frayed cable produces an unusual scratching noise when the window is operated up or down. The movement of the window might become jerky too.
It might jam or have troubles going all the way up or down. When a cable or other part of the window regulator breaks completely (see the photo), the window won't go up at all, even though you can hear the window motor is running. Sometimes the window glass might even fall down inside the door. The window motor might jam too.
Broken window regulatorBroken window regulator cable
If one of the clamps that hold the glass breaks or a clamp bolt loosens up, the window may feel loose or going up crooked. The same might happen if a cable comes off one of the pulleys.

In some cars, a window regulator is made with geared arms instead of cables, see this photo. When teeth on a geared arm wear out, the window will also move jerky and it will sound like a gear is skipping.

How much does it cost to replace a window regulator? Replacing a window regulator at a dealership will cost from $190 to $350 for an average car. Getting the job done in an independent shop might be less expensive. In some cars the window regulator comes as one piece with the motor. An OEM window regulator (part) is priced around $60-$180. An aftermarket part will be cheaper ($30-$70). Depending on a car it may take up to 1.5-2.0 hours to replace a window regulator. To do the job a mechanic will have to remove the door panel (cover) and a few other parts.

After the job is done, check if all the functions of the power windows work correctly. In some cars, the control module needs to be reset after repairs, or the AUTO function will not work correctly or the window will go up and then reverse on its own. Also check if the power lock and mirror work.

Does the window regulator need any maintenance? No, it's a maintenance-free part. The only part of the window mechanism that may need some maintenance is the rubber window run channel.
If the window goes up too slow, or squeals when moving, cleaning and lubricating the window run channel with a silicone lubricant may help. If a top portion of the window run channel is pinched, it may also cause the window to reverse from the top position on its own. A worn-out window run channel may also cause a wind noise coming from the window. If a window run channel is excessively worn out or pinched, it will need to be replaced. Replacing a rubber window run channel in one door costs $105-$170.

Is the window regulator covered by the factory warranty? Yes, in most cars, a window regulator is covered by the basic factory warranty. Several manufacturers issued recalls addressing problems related to a window regulator.