My driver side window quit working on my '97 Z28 so I bought an AC Delco replacement motor and regulator, put it in and it worked well for a few months. Now it is slow to close and one time it stopped moving until it cooled off. I'm a bit bummed and assume that the new motor must be going bad (still under warranty but a real hassle to remove it, send it back and then put a new one in). Before I do anything else I'm wondering if there is any way without taking the door apart again to figure out if it really is the motor and not something else. The passenger side works fine, so not the fuse. I've ohm'd out the switch and it opens and closes like it should. The interesting thing I found is that if I check the resistance through the motor (blue to brown wire on the driver side) downstream of the switch and the auto down relay I'm getting about 85 ohms. When I check the same on the passenger side (different wire colors than driver side, I forget exactly which) I get zero ohms. The motor that I removed ohms out at something like 650 ohms. I'm taking this as a sign that my new motor is in fact on its way out but was wondering if I am missing anything. From the schematics there is nothing that should be adding resistance to the system once past the auto-down relay and I'm pretty sure the brown to blue wires taken from the switch are in fact downstream of the relay. The only other thought I have is maybe the connector inside the door panel itself to the regulator/motor connector could have some corrosion or something. Does anyone have any opinions? Thanks for any help.

 

I have pretty much the same issue with an AC Delco (made in China) window motor for my '97. Pretty sure there is a brush stuck or something. Take it out. Drop it on the ground. Plug it in and give it a try. It will probably work great. Mine lasted a month after that and same thing. I pulled apart and cleaned the old one I originally took out and it works fine. Just put it back in yesterday.

 

Thanks for posting. If it is something like that I'm real disappointed in Delco since I paid quite a bit more for a Delco replacement than a generic Chinese knock-off specifically because I figured they would be more reliable.

 

I contacted the place I purchased it through on Amazon. They said send the motor back and they will send a replacement. I paid $30 on Amazon.

 

I bought the whole motor and regulator from Amazon at about $88 delivered.


Window has now completely stopped working and ohm readings now about 88 kOhm so I think it is fully shot now.

 

sounds like it

 

Just as a final follow up for anyone's future use -


Turns out the issue was the electrical connector inside the door panel not the new motor. The wiring at the harness was not making good connection - the plastic of the harness is breaking down a bit with age.