94 SC Power Window Motor

I started having issues with the driver's power window motor about a month ago. The first symptom was that the motor wanted to keep running after the window was all the way up or all the way down. Eventually it started slipping (typical plastic plug problem).

Today I pulled the motor out and went about cleaning it and replacing the 3 plastic plugs. When I replaced the motor, it still wants to keep running both after the window is completely raised and lowered. When this happens, a loud knock occurs and the window will jump slightly and this will continue until you release the switch.

To the best of my knowledge (I reviewed the wiring schematic as well) there is no separate limit switch. The motor should just stop trying to turn when it meets enough resistance. The plastic gear itself looked to be in pretty good shape. However, now I am wondering if the teeth on it could be worn just enough to slip on the worm gear when enough force is met, but prior to the point where enough force is met to prevent the motor from continuing to try to run.

Autozone has a Dorman replacement motor for around $56. It looks a little different from EOM (part of the housing is plastic, etc.). The also sell a kit that includes the plastic plugs and the plastic gear for around $20.

I'm tempted to try replacing the plastic gear. Has anyone had a similar experience? Has anyone tried the Dorman motor? They also show a Cardone motor which requires a core charge (I think it is around $74 plus $15 core charge for a total of $89) but it is not stocked and I don't know if it is still available.

Best Regards,

Ted

I, recently, rebuild the power window motor on the driver's side of my '97. I used the rebuild kit from SuperCoupePerformance.com and had awesome good results.

Just the basic rebuild kits with the three new plastic plugs is enough in most cases - just be sure the unit itself is worth keeping...check that the center shaft that sticks out of the housing, that the gear and plugs spin, on isn't loose in the housing.

If this is the case, a fresh unit is your best bet.

KMT,

The shaft in this motor felt solid and the motor seems to have plenty of power. The kit I got only contained the 3 plastic plugs.

However, there is a kit that contains both the splined plastic gear, the plugs, and the 9 tooth metal gear.

If the teeth on the large splined plastic gear that meshes with the worm gear do you think it could cause the motor to want to continue running on when it reaches full stop for the window mechanism at both top and bottom of its travel? If not, and there is not separate limit switch/sensor (which I don't believe there is), then I will have to replace the motor.

Thanks,

Ted

Can you buy another complete unit and plug it in and test?

Keep the receipt

The switch just reverses current thru the motor...is the overrun in both directions? Can you swap in another switch long enuf to test?

If the motor simply spins it means the gears/plugs are disengaging somehow and/or ignoring the load, which would mean the plugs are gone enough to let it travel, but not load up, or the housing center shaft is moving, housing is cracked, etc.

KMT said:

Can you buy another complete unit and plug it in and test?

Keep the receipt

The switch just reverses current thru the motor...is the overrun in both directions? Can you swap in another switch long enuf to test?

If the motor simply spins it means the gears/plugs are disengaging somehow and/or ignoring the load, which would mean the plugs are gone enough to let it travel, but not load up, or the housing center shaft is moving, housing is cracked, etc.

Click to expand...

I can get the Dorman unit at Autozone right now, however, most places don't take returns on electrical components. I replaced the plastic plugs yesterday, so I think they are fine. The housing center shaft felt solid. I am wondering if maybe the larger plastic gear that meshes with the worm screw is worn enough to where it starts to disengage from the worm gear if the load gets high enough.

As I mentioned in prior post, The Dorman unit looks a little different and part of the housing is plastic (the part where the gears are located) which isn't too inspiring. It is in stock at Autozone or was yesterday. The Cardone, which looks more the OEM, and requires a core charge, must be ordered and is about 50% more expensive excluding the core charge.

Thanks,

Ted

AZ will take it back...they don't care. Deal with them.

I ended up buying the Dorman unit from Autozone and installed it on Labor Day. At first I thought it wasn't going to work. The motor was running, but the window was not moving at all. Then it was behaving like the original (would go up and down but continue running on after loud pop and lurch at the extreme upper and lower positions).

It turned out the 9 tooth gear on the motor wasn't meshing completely with the gear on the window regulator. I couldn't find any unusual play in the regulator so I loosened and refitted the motor. After fiddling with it for awhile it started working normally. Now I am wondering if the original motor is probably fine as well. The plastic plugs were definitely shot, so it needed work anyway, but the original symptom was the same as the new one was when the gears on the motor and the regulator weren't matching up completely.

Maybe there was enough wear on the old motor's 9 tooth metal gear to cause it to disengage from the gear on the regulator. The shaft that it mounted to in the motor housing seemed stable so I don't think that was the culprit.

Anyway, I'll hold onto the old motor just in case...

Thanks to all for the responses. I'll update this thread if issues arise in the not too distant future.

Best Regards,

Ted

Are you sure you aren't having a switch problem? When you say the old motor kept running with the POP noise, was that only when your finger was still on the switch? Or did it keep running without any input from you?