76 rear window problem

[JAR76]

So, I have had this car for about a month now. All the receipts show all four motors were replaced last year. Today I decided to air her out a little, so I opened up all the widows for about six hours. I decided to go for a ride a lo and behold, the driver side widow will not go up. I tried slamming the door a few times while holding the switch in the up position. No luck. I just now opened up the door panel and will try to help the window up with a suction cup. Any ideas?
Thanks

PS I just noticed when I put the other three switches in the up position you can notice a slight dimming of the interior lights but not with the one in question.

[Lee]

You probably know this by now, but that window isn’t going to move if the motor doesn’t turn.
Since it’s only one window, if it were my car, I’d pull out the plug for the window switches, and try jumpering 12v to that motor. If it moves, then it’s the switch. If you get nothing, it’s probably the motor.

[JAR76]

Thanks for the reply. I tried both switches. And yes, I know now that that window isn't going anywhere. The thing is after tapping on the motor with a small hammer it did go up about four inches. Now I have lost my access to the motor because it is being blocked by the regulator. I am guessing that I will now have to somehow remove the glass in the position it is currently in. I have tried using a 12-volt converter on the two-wire harness that goes to the motor but to no avail. I will try attaching the 12-volt converter to the actual switch tomorrow. I am at the point where it is time to walk away and regroup.

[TonyC]

Okay, I got answers to questions I was going to ask. I do not believe the motor is your problem. It must be wiring somewhere; if it acts the same from either switch, the problem might be close to the motor.

If the motor moves any, it's okay; motor failures are total. Sporadic failures are current-connection issues.

---Tony

[JAR76]

Thanks, Tony. I will try to isolate a wiring problem in the AM. I sure don't want to take out the glass and I am sure I will be thinking about this all Nite.

PS all four motors were replaced. The one in question was replaced in 2021. When I purchased the car, the seller took me to see his mechanic about the car and he is well versed in older cars. I only wish there was someone like him in my town.

[JAR76]

After looking at the service manual the rear switch gets it current and ground from the driver's door panel. I think I will start there.

[1Bad55Chevy]

I work on cars for a living at the BHPH car lot my wife and I own. I will say since COVID started in 2020 the quality of the aftermarket parts supply is 100% shit. Just because the motors were replaced in 2021 dosen't mean a damn thing anymore. It would probably be better if the seller told told you he replaced the motors in 1995. lol

[TonyC]

That is plausible...but if the parts were manufactured before the CCCS and just happened to be available after, then nothing to be concerned about.

Starting at the ground point is as good a place as any to start. Many electrical issues usually occur due to bad ground; hopefully the case here.

---Tony

[kellyz]

Sounds to me like the rubber/plastic "cushions" in the motor are shot. Especially if you got it to move 4 inches. Problem is that you can't verify that until you get the motor out. I have had three lincolns and NEVER had a bad motor. Just those cushions or bushings.

[JAR76]

Thanks, guys, for all the advice. Swapped out the motor today and all is well. Turns out that the motor was swapped out two years ago with a Dorman motor.

[Dan Szwarc]

The Dorman only lasted a few years? That's... sad.

[1Bad55Chevy]

Dorman has become complete trash. Try installing their AC actuators on some late model junk sometime, you will love pulling the dash back out a week later to do it again when they start popping. Their LS rear main seal plates are total garbage and will start leaking again within a month. Also their LS VLOM plates are total trash, I have yet to see one of those make 6 months.

Probably the only thing out there that's worse then Dorman is A1 Cardone. It seems like there is zero QC with any of the Cardone products they re manufacture. I keep saying that the parts have gone to complete shit since 2020 and OEM replacements are not much better..

[JAR76]

Unfortunately, the previous owner replaced all four and did not keep the originals. I wish I had them to rebuild while the windows are still in the up position. Makes it much easier to replace without having to remove the window.

[LithiumCobalt]

It has been going on longer than just from 2020. Chi-comm trash has been flooding the US market for decades

[Lee]

My first job was as a parts jockey for a little independent store back in the seventies. Dorman was top-line merchandise back then. Too bad.