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A Guide to Replacing the Window Motor in Your 1987-1991 Buick LeSabre

Here is what you need to know before buying a new aftermarket window motor for your classic Buick LeSabre.

4 minutes to read 1987-1991 Buick LeSabre
Difficulty
3/5
Est. Time
2 hrs
DIY Doable?
✅ Yes
Shop Labor
$150-$250
Used OEM Price
$20-$60
⚠️ Drivable, but... — Yes, but a window stuck open is a security risk, and a window stuck closed is an inconvenience and potential safety issue in an emergency.
Key Takeaways
  • The window motor works with a plastic 'regulator tape' which is a common failure point on these cars.
  • You must drill out the factory rivets to remove the old motor; new parts come with bolts.
  • Brands like Dorman and Cardone are reliable aftermarket choices that offer good value.
  • Always test the new motor before you put the door panel back on completely.
The window motor in your 1987-1991 Buick LeSabre is a small electric motor inside each door. When you press the window switch, the motor turns a gear. This gear moves a flexible, plastic-toothed track called a 'regulator tape'. This tape is what pushes the window glass up or pulls it down. Without a working motor, your power windows will not function, leaving the glass stuck in place.

Is Your LeSabre's Window Motor Failing?

A failing window motor in these classic Buicks can be a nuisance and a security risk. Because these cars use a plastic regulator tape system, symptoms can sometimes point to the tape or the motor. Often, it's best to inspect both. Here are the common signs of a bad window motor:

  • Slow Window Operation: The window struggles to go up or down, especially when going up. This can be worse when the engine is off and alternator power is not available.
  • No Movement, Possible Noise: You press the switch and hear a clicking or grinding sound from inside the door, but the window doesn't move. This often means the motor is trying to work, but the internal gears are stripped.
  • Window Drifts Down: The motor's internal gearing may be worn out, failing to hold the window in the fully closed position.
  • Completely Dead: There is no sound or movement when you press the switch. Before blaming the motor, it's wise to check the fuse and the switch itself.

A Common Point of Failure: The Regulator Tape

On these 1980s and early 90s GM cars, the plastic regulator tape is a very common failure point. Over decades, the plastic becomes brittle and the teeth can strip, causing the window to bind or get stuck. If your window is slow or makes noise, the tape could be the problem, not just the motor. Many owners choose to replace the motor and inspect or replace the tape at the same time.

Choosing the Right Aftermarket Window Motor

For a vehicle of this age, aftermarket parts offer excellent value. Original Equipment (OEM) parts can be difficult to find and expensive. Aftermarket brands often provide comparable quality for less money. Here’s a breakdown of the brands available:

Tier 1: Reputable Aftermarket Brands

  • Dorman: A well-known and trusted brand in the aftermarket industry. Dorman sometimes redesigns parts to be more reliable than the original. They have a reputation for decent quality and often come with a lifetime warranty, making them a solid choice for most owners.
  • Cardone (A1 Cardone): Another major brand that offers both new and remanufactured parts. Cardone is known for its extensive catalog, especially for older vehicles, and is generally considered a reliable OEM alternative.

Tier 2: Budget-Friendly Options

  • Skyward / SKP: These are value-oriented brands. While they can get the job done for a lower price, their long-term durability may not match that of more established brands. They can be a good option for a car that is not driven daily.
  • Replacement: This is often a private-label or generic brand. The quality can vary, but they are typically the most affordable option. If budget is your primary concern, this brand will restore function, but may not last as long as a premium aftermarket part.

Installation Pro-Tip

The original window motor is held to the regulator with steel rivets. You will need to drill these rivets out to remove the old motor. Your new aftermarket motor will come with a set of small nuts and bolts to use for installation. Before you put the door panel back on, plug the new motor into the switch and test its operation to make sure everything works correctly.

Aftermarket Window Motor Cost for 1987-1991 Buick LeSabre

Part Type Estimated Cost
New Aftermarket Motor $37 - $178
New OEM Motor $50 - $135
Shop Labor $150 - $250

Frequently Asked Questions

Do I have to replace the entire window regulator assembly?

No, you can replace just the motor. However, given the age of the vehicle and the common failure of the plastic regulator tape, it is highly recommended to inspect the tape for wear, brittleness, or stripped teeth while you have the door panel off.

Is the front window motor the same as the rear?

Often, the motors are different for the front and rear doors, and sometimes even for the left and right sides. Always confirm the exact fitment for your vehicle's specific door before ordering.

Do I need special tools for this job?

You will need a drill with a sharp drill bit to remove the factory rivets holding the old motor. Otherwise, the job requires standard hand tools like a socket set, screwdrivers, and trim removal tools to take off the door panel.

Why did my window stop working after I installed a new motor?

First, check that the electrical connector is fully seated. Second, ensure the window is not binding in its tracks, which can overload the new motor. The regulator tape system must be properly aligned. Finally, a faulty window switch or a blown fuse could also be the culprit.

Technical Specifications

OEM Part Numbers: 12497971

This vehicle uses a window motor paired with a plastic, toothed regulator tape system to move the window glass. The motor is attached to the regulator assembly via rivets from the factory.

Wrenchy
Article researched & written by
Go-Parts' AI research assistant. Every article is backed by live web research, verified OEM data, and real technician knowledge — so you get accurate, up-to-date information you can trust.
Meet Wrenchy → Updated Apr 19, 2026

The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.

Year Coverage
This article covers the Window Motor for:
  • Buick LeSabre: 19871988198919901991
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