1992 Pontiac Grand Prix



October, 13, 2012 AT 9:13 PM

Hello, I'm having a problem with my 1992 Grand Prix LE passenger front power window. I seem to remember that if someone closed the window too high in the past (kept their finger on the up button once the window was closed), it would bind up and the window wouldn't work afterwards. To clear this, you could usually go over railroad tracks (or bumpy road) with a finger on the down button and the drivers window would start working fine until it happened again - my son used to do that when he drove the car until I got it into his head what was going on. That trick isn't working to open this window - passenger front.

I've checked voltage at the motor and do have 12v on the blue wire when depressing the switch but haven't tried grounding the other wire (brown) yet as I've looked for a wiring diagram. I'm not anxious to drill out the rivets to replace the motor but I guess if it comes to that.

In the meantime, how might I check the window 'regulator'? I don't know much about how these regulators interact with the motor and am anxious to learn more. I'm trying to get this car going again after a couple of years in storage as it waited for my daughter to turn 16. Thanks for any help.


18 Answers



October, 13, 2012 AT 9:16 PM

The motor sounds like it has failed. Replace the window/regulator assembly.

When it does not work, the jolt is what brings the motor back on line.




October, 13, 2012 AT 9:25 PM

You should test the motor first. It used to work previously because the carbons were still able to work after some jolting/vibrations.

If the motor does not respond when grounding the wire as you mentioned, you know the motor is bad. However if it starts to work, use the switch again and retest. If it stops working or continues to work, it is good for now but the motor is due for replacement. It is going to fail anytime.



October, 13, 2012 AT 9:26 PM

I saw what I believe was the motor/regulator combo at Autozone for something like $40. Do they always come together? Also, don't know if you guys may know but there appears to be 4 rivets holding the assembly in, sound about right?



October, 13, 2012 AT 9:40 PM

Motor can be replaced separately for factory regulators but for after market the design might be different it is best to get the complete assy.

Actually there should be 3 rivets for the factory regulator and if you are replacing the motor itself, you need to drill out the rivets.



October, 13, 2012 AT 10:19 PM

Thanks for the replies guys. In the attached pic, I've numbered 4 rivets. I'm guessing that this change-out requires drilling the first three (numbered 1-3). At the bottom right I superimposed a blown up view of the rivets - do you think I should try to cut what's protruding as flush as I can with a pair of dikes and then drill out as necessary what's remaining until I free up the motor? Also, any surprises I should expect with the window once I free up the motor assy? (window is currently in the up position).

I'm guessing too that the motor is frame grounded since I have power on blue in the switch up position and power on brown in the switch down position. I hoped for a small miracle by tapping on the motor while holding the switch down but not today...

Here's the motor at Autozone - any thoughts?

Thanks again



October, 13, 2012 AT 10:30 PM

The picture is for the motor and that is attached to the regulator by 3 rivets.

The 4 rivets is for the regulator assy, which you need to drill out to get the assy off the door before you can replace the window motor.

Removal (Sedan - Front)

1. Remove door trim panel.

2. Remove water deflector.

3. Remove rivets using 1/4" drill bit.

4. Remove regulator by disengaging regulator arm from sash channel.

5. Remove electrical connector to motor and remove regulator through door inner access hole.



October, 18, 2012 AT 8:07 PM

Have any of you guys only replaced the motor on a Pontiac? I'd read one article somewhere about the counter balance spring really creating an issue for one guy. It 'looks' like a person could just drill the rivets and replace the geared motor without a lot of other hassle but I thought I'd ask. I ordered a Dorman motor to do the replacement and hope to get into it this weekend.



October, 19, 2012 AT 5:13 PM

Not on a Pontiac for me but other makes are similar except some don't have any springs. The spring would tend to cause the regulator gear to overshoot and prior to taking the motor out, hold the scissor of the regulator in place by means of strings etc would prevent it from overshooting. Marking the springs direction would help in the event the regulator manages to run free.



October, 19, 2012 AT 5:27 PM


Removal (Front)
CAUTION: Steps 2) and 3) must be performed once regulator is removed from door. The regulator lift arm is under tension from the counterbalance spring and can cause personal injury if the motor is removed without locking the sector gear in position.

1. Remove window regulator. See WINDOW REGULATOR.

2. Drill hole through regulator sector gear and backplate. Do not drill hole closer than
1/2" (13 mm) to edge of sector gear or backplate.

3. Install bolt and nut to lock sector gear in position.

4. Drill out ends of three rivets using 1/4" drill bit.

5. Remove motor and remaining portions of rivets. See Fig. 30.


1. Install new motor to backplate. See Fig. 30.

2. Install rivet to motor at bottom location using ball peen hammer.

3. Clamp motor to backplate using locking pliers.

4. Remove bolt and nut securing sector gear.

5. Supply power to regulator to gain access for remaining two motor rivets.

6. Install two rivets.

7. Remove locking pliers.

8. Install window regulator. See WINDOW REGULATOR.



1. Install regulator through access hole and attach regulator arm to sash channel.

2. Install electrical connector to motor.

3. Install rivets using 1/4" x 1/2" Peel-type rivets.

4. Install water deflector.

5. Install door trim panel.



October, 20, 2012 AT 2:05 AM

My gosh what a deal it is to replace this motor. "Regulator sector gear and backplate"? I am assuming the 'regulator sector gear' is the one that meshes with the motor gear. To drill a hole through it and bolt it so the spring doesn't come un-wound seems like quite a task. Guess I'll see. Did this come from a GM service manual so far as the 'how-to' ? Would have been great had they mentioned a size. I guess for lack of a size, I'll try to go for a 1/4" bolt.

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