2018-2020 Buick Regal & Holden Commodore Wiper Motor: Symptoms and Replacement

Symptoms of a Failing Windshield Wiper Motor

For the 2018-2020 Buick Regal and Holden Commodore, the windshield wiper motor is generally a reliable part with no widespread reported issues. However, like any electrical component, it can fail. If you're experiencing problems, look for these common symptoms before deciding on a replacement.

• Wipers Move Slowly: You select a high-speed setting, but the wipers move sluggishly across the glass. This can indicate the motor is wearing out and losing strength.
• Wipers Only Work on One Speed: The motor may function only on the highest speed setting, while lower or intermittent speeds do not work at all. This often points to a failure in the motor's internal circuitry.
• Wipers Won't "Park" Correctly: When you turn the wipers off, they stop immediately in the middle of the windshield instead of returning to their resting position. This is a classic sign of a bad park switch inside the motor assembly.
• No Movement at All: You turn the wiper switch on and nothing happens. While this could be a completely failed motor, it's crucial to check the fuse first.
• Humming or Grinding Noise: You may hear a distinct humming or grinding sound coming from the base of the windshield (the cowl area) when the wipers are activated. This often means the motor is receiving power but its internal gears are stripped or jammed.

Known Issues, Recalls, and Technical Service Bulletins (TSBs)

As of early 2026, there are no specific recalls or Technical Service Bulletins (TSBs) from General Motors or the National Highway Traffic Safety Administration (NHTSA) for windshield wiper motor failure on the 2018-2020 Buick Regal. Searches of owner forums for both the Buick Regal and its Australian counterpart, the Holden Commodore ZB, do not show this to be a common complaint. Recalls issued for these vehicles concern the braking system software and front seat welds, not the wiper system. This suggests that motor failure is an isolated issue rather than a widespread defect.

Diagnosing the Problem Before You Buy

Don't assume the motor is bad without a quick diagnosis. The problem could be simpler and cheaper to fix.

1. Check the Fuse: This is always the first step. A blown fuse will cause the wipers to stop working completely. Consult your owner's manual for the fuse box diagram and locate the fuse for the windshield wipers.
2. Listen for the Motor: Turn the wipers on and listen carefully at the cowl area. If you hear a humming sound but the wipers don't move, the motor is getting power. The problem might be stripped gears inside the motor or a seized wiper linkage (also called a transmission).
3. Check the Wiper Linkage: Sometimes the arms and pivots that connect the motor to the wipers can get corroded and bind up, putting a heavy strain on the motor and causing it to move slowly or not at all.
4. Test for Power: If you have a multimeter, you can perform a definitive test. Disconnect the electrical connector at the wiper motor. Have a helper activate the wiper switch while you test the terminals in the connector for 12-volt power. If you have power at the connector but the motor doesn't run, the motor itself has failed.

Buying a Used Windshield Wiper Motor: What to Check

Since new aftermarket options for this specific motor are not readily available, your choice is often between a new OEM part from a dealer or a used OEM part from a recycler. A low-mileage used motor can be a reliable and cost-effective solution.

Why a Used OEM Motor is a Smart Choice

The original GM motor is designed specifically for your vehicle's electrical system, ensuring correct speeds and proper parking function. Cheap aftermarket parts, when available, can sometimes have shorter lifespans or compatibility issues. A used OEM motor that has been tested and comes with a warranty from a reputable seller is often a better value than a questionable new part.

Inspection Checklist for a Used Motor:

• Part Number Verification: For the 2018-2020 Buick Regal (Sportback and TourX), the correct OEM part number is 39122787. Always match this number.
• Holden Commodore Note: The 2018-2020 Holden Commodore ZB is built on the same platform, but may use a different part number (some sources show 13471429). While the parts may be physically similar, interchangeability is not guaranteed. Holden owners should verify the number on their original part before purchasing.
🎬 Watch: Replacing a Holden Commodore wiper motor and linkage
• Connector Pins: Inspect the electrical connector on the motor. The pins should be straight, clean, and free of any green or white corrosion. The plastic housing should not be melted or cracked.
• Output Shaft: Look at the splined metal shaft where the wiper linkage attaches. The splines should be clean and well-defined, not stripped or twisted.
• Housing Integrity: Check the motor's case for any cracks, severe rust, or signs that it has been opened or tampered with.

Cost Comparison

Prices can vary by supplier and location, but this table provides a general estimate for the front windshield wiper motor on a 2018-2020 Buick Regal.

Replacement Overview

Replacing the wiper motor is a manageable DIY job for someone with basic tools and mechanical experience.

• Difficulty: 3 out of 5
• Estimated Time: 1.5 hours
• Tools Required: Socket set (metric), trim panel removal tools, and a windshield wiper arm puller.

A wiper arm puller is a small, inexpensive tool that safely removes the wiper arms from their splined posts without causing damage. Prying them off can easily break the wiper arm or the linkage underneath.

Basic Steps:

1. Mark the wiper arm positions on the glass.
2. Disconnect the negative battery terminal.
3. Pop off the plastic caps at the base of the wiper arms and remove the nuts.
4. Use the wiper arm puller to lift the arms off the posts.
5. Carefully remove the plastic cowl cover at the base of the windshield. It is held on by clips and possibly screws.
6. You can now see the wiper motor and linkage assembly. Disconnect the motor's electrical plug.
7. Unbolt the entire assembly (motor and linkage) from the vehicle's firewall.
8. On a workbench, unbolt the old motor from the linkage and attach the new motor.
9. Reinstall the assembly, but do not attach the wiper arms yet.
10. Reconnect the battery and electrical plug. Briefly turn the ignition and the wipers on and then off. This allows the new motor to move to its correct "park" position.
11. Install the wiper arms, aligning them with the tape marks you made earlier.
🎬 See this complete guide on replacing a windshield wiper motor

Frequently Asked Questions (FAQ)