Power window issue

[ZacharyDouglas1992]

I am having a unique power window issue that I have not encountered before so I figured I’d pick the expert brains here. I bought a power window harness from a member here that I’ve had quite a bit of trouble with. I have it mostly working now but I have an issue with the driver door. It goes up smooth as butter. It goes down choppy, in rhythmic little spurts. I’ve ruled out the motor as it’s done it with 3 different motors. Even when it’s just the motor itself and no load on it whatsoever. Any thoughts?

[Pontiac1976]

I’ve ruled out the motor as it’s done it with 3 different motors

Since you say that, first think comes to mind is have you greased the tracks check the rollers. Make sure there free and not cracked wore uneven or sized.
Check that all the tracks are not gummed up or rust up inside. If you watch the movement of the regulator when going up and down you should see that it will rub the roller at different places in the tracks when going up from down. Should help you know where the grease is need extra attention in the tracks.

[Willowrun]

Agree with above. R&R or replace the regulators.

[ZacharyDouglas1992]

Originally Posted by Willowrun

Agree with above. R&R or replace the regulators.

Thanks for the replies. I owe you guys more info on this. Unfortunately it isn’t that simple. I have plugged in 2 new motors to the harness without the regulators attached and it does it when it’s just the motor itself. It rolls smooth in one direction, and then it’s choppy in the other. I had a custom harness made from a member (or former member as it looks) that has modules for express down. The module clicks in the same rhythm as the motor when it’s doing it’s choppy thing. I tried swapping it with the other 3 identical modules on the other doors, but it’s always an issue on the driver doors window itself. All of the other doors work as they should from their own switches as well as the driver door switch. Something about the way it’s set up is likely the issue, but I have no diagram and no understanding of how these systems work. It sat at a body shop for 8 years after I purchased the harness so it is what it is. Ultimately I may consult an automotive electrician cause I don’t want this holding up my wrapping up of the project.
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[roboticjunky]

I'm going to guess who you got the harness from.

So check these threads for info and see if they help you.

http://67-72chevytrucks.com/vboard/s...t=express+down

https://www.elcaminocentral.com/thre...h-video.61841/

https://www.elcaminocentral.com/thre...l-parts.60418/

[ZacharyDouglas1992]

Originally Posted by roboticjunky

I'm going to guess who you got the harness from.

So check these threads for info and see if they help you.

http://67-72chevytrucks.com/vboard/s...t=express+down

https://www.elcaminocentral.com/thre...h-video.61841/

https://www.elcaminocentral.com/thre...l-parts.60418/

Thank you guys for the replies. Yep I’m sure you know exactly who. I’ve had to do so much work to this harness I wish I’d just made my own from scratch at this point. That being said, I appreciate those links they may help me get the last door figured out. At this point if I can just get the other 3 doors working with express down I’d be happy to have the driver door just work like a normal window.
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[Sabaka454]

Unplug the motor and install a volt meter in its place. Measure the voltage when holding up and then down. Is this a reproduction harness or a relay harness?

[ZacharyDouglas1992]

Originally Posted by Sabaka454

Unplug the motor and install a volt meter in its place. Measure the voltage when holding up and then down. Is this a reproduction harness or a relay harness?

It’s a custom harness which has been the root of all my issues thus far. I figured it out. The wiring from the express module (25614182) had two of the wires swapped, so it was having issues switching the polarity like it should. Out of frustration I rewired the driver door entirely from scratch and that turned out to be the issue. Thank you for all the replies. In the future if anyone is doing this express down upgrade and the motor only works correctly in one direction, chances are it’s in the wiring between the module and the switch.
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[Pontiac1976]

Thanks for the update glad you got it working.

[LT7A]

Good work. Thanks for letting us know.