Corvette C5 Power Window Motor Rebuild
This procedure is only appropriate if:
The motor is getting power but not working. Unplug and check with voltmeter first.
The cables and all other components are in good condition. Otherwise you will need to replace the whole assembly.
The connector at the motor is making good connection. Some have reported problems with the connector itself.
If the brushes are too worn or if the commutator is melted/ burnt, it cannot be easily repaired. May as well just buy another motor.
First, pull the door panel and speakers. I used some paper towels around the big opening to keep the black sticky stuff from getting all over the place. Remove the switch assembly from the door panel and plug it back into the harness for testing. Unplug the window motor and check for power with a voltmeter. Here's a picture of the plug, and the button you have to push to pull it out:
Once you have determined that the motor is getting power, remove the regulator assembly. Once again, other instructions are very detailed how to do this. On my car ('99), the rubber on the window clamps was stuck very securely to the glass, so I had to remove the bolts completely and break the glass away from the rubber. If the clamp half sticks to the window, that's even better, it will assure you put the window back in the same place. Otherwise mark it.
Here is the regulator assembly removed :
Next, I pulled the can off the motor to inspect. This pic was actually taken during reassembly after it was all cleaned up. Now is probably the best time to remove the brush retaining springs to relieve the pressure on them. Refer to post #5.
I was able to pull the armature free from the regulator assembly without disassembling it, but then I couldn't get it back together. I recommend just taking it apart to begin with.
Rotate the armature to equalize the tension on the springs, if needed, and remove the top plate. Take note of where the cables are routed.
Here's a pic of the cover removed
*NOTE: THE CABLE CLOSEST TO THE MOTOR IS IN THE WRONG PLACE. DO NOT REASSEMBLE THIS WAY OR THERE WON'T BE ENOUGH TENSION IN THE CABLES*
(Ask me how I know.)
The spool slides right out. It looks like a mess, but goes back together relatively easy.
Finally, remove the cover and the gear. The armature will then slide out easily
Here is the motor disassembled. Note all the black junk that fell out.
A close-up of the dirty brush housing and brushes
And the armature
I used a electronics cleaner to spray everything off. On the armature, I used a dental pick to clean the slots on the commutator and very fine sandpaper to clean it up.
I found that one of the brushes had been contacting the elevated pads on the commutator, and I assume this is the reason for all the black dust. As a precautionary measure, I cut the grove a little larger and deeper to prevent further contact. Be very careful with the brushes, they are brittle and fragile. I cleaned them by scraping lightly with a razor blade.
Once everything is clean, reassemble in reverse order. The safest way to put the brush holder back onto the armature is to remove the caps and springs that hold the brushes in. Here are pics of the caps disassembled and assembled. I reached in with a dental pick to undo the clips. Keep a finger over the cap as you're removing them, as the spring has quite a bit of pressure on it.
There was plenty of grease inside the gear housings to re-lube the motor shafts (both ends) and the gears during reassembly.
When putting the spool back into place, I wound up the wires and clipped the green cable ends into place then slid the spool onto the splines.
Once everything is put back together, take it back to the car to verify that it works. My first time, the window operation was reversed. I'm not sure what caused this, but I took everything apart and put it back together, and the only thing I did differently was rotate the motor housing ("can") 180deg. This time it worked. Not sure if that was the problem or if it was something else. If anyone has input, I'd appreciate it.
A couple more notes on reassembly: The rear lower track bolt is adjustable. As you're removing the nut off the stud, hold the stud to assure it does not turn. Same with reassembly. The front lower track bolt is also adjustable in a slot. If you forgot to mark where it was, you can probably look closely and see a dust/ wear ring where it was previously mounted.
And here is where the zip-tie retainer clip fastens to the door. It is important, as it keeps the cables out of the window as it goes down.
