power window ground?
Thread Starter
Racer
Joined: Nov 2009
Posts: 486
Likes: 1
power window ground?
My windows will not roll up or down on the driver side. I have 12 volts at the terminals but when I plug them into the motor and hit the switch it drops down to 8 volts and does nothing. How to use a wire from the battery street to the terminal which work before but now it will not work either.
Motor is new and made sure it works. I rebuilt the inside track assembly
Where is the ground from the motor to the car?
Motor is new and made sure it works. I rebuilt the inside track assembly
Where is the ground from the motor to the car?
Le Mans Master
Joined: Aug 2006
Posts: 7,419
Likes: 1,555
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
The motor case is the ground.
My windows will not roll up or down on the driver side. I have 12 volts at the terminals but when I plug them into the motor and hit the switch it drops down to 8 volts and does nothing. How to use a wire from the battery street to the terminal which work before but now it will not work either.
Motor is new and made sure it works. I rebuilt the inside track assembly
Where is the ground from the motor to the car?
Motor is new and made sure it works. I rebuilt the inside track assembly
Where is the ground from the motor to the car?
The two terminals at the end of the motor get 12 volts one at a time. One terminal makes the window go up & 12 volts to the other is for down.
Many times the switches don't pass enough current so swap left for right and see what happens.
Thread Starter
Racer
Joined: Nov 2009
Posts: 486
Likes: 1
The power window motor case is bolted to the door which is grounded ( through the hinges and bird cage).
The two terminals at the end of the motor get 12 volts one at a time. One terminal makes the window go up & 12 volts to the other is for down.
Many times the switches don't pass enough current so swap left for right and see what happens.
The two terminals at the end of the motor get 12 volts one at a time. One terminal makes the window go up & 12 volts to the other is for down.
Many times the switches don't pass enough current so swap left for right and see what happens.
Le Mans Master
Joined: Aug 2006
Posts: 7,419
Likes: 1,555
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
With a ground from a battery to the case and a positive to one or the other terminal on the end of the motor it should run if good.
Sometimes the brushes inside get stuck and a Bubba quick fix is to smack the case with a plastic mallet.
Sometimes the brushes inside get stuck and a Bubba quick fix is to smack the case with a plastic mallet.
Thread Starter
Racer
Joined: Nov 2009
Posts: 486
Likes: 1
Still not working right. Now it did not work from the battery. Acted like it was jammed??? I removed the motor and r-surfaced all the ground connections inside the door. It worked great for 5 times then stopped again. I am not quite sure anymore... I think I will take it to Austin Corvette and see what they can figure out. Its just a PITA getting the car up there since I live 2.5 hours away. I think its time to have a beer haha 
Safety Car
Joined: Oct 2007
Posts: 3,729
Likes: 267
From: Austin Texas
Corvette of the Year Winner 2017
2016 C3 of Year Finalist
if you can not bench test reliable your motor has issues,
Gnd the motor to the battery, apply +12 to one terminal or the other,
1 terminal is up, and 1 terminal is down.
Do not drive to the end of motor travel.
Vettes reliy on the door hinges for Gnd. (Another bad Engineering ideal)
I run an addidtional Gnd wire, with the harness and attach right to the motor from the birdcage.
Gnd the motor to the battery, apply +12 to one terminal or the other,
1 terminal is up, and 1 terminal is down.
Do not drive to the end of motor travel.
Vettes reliy on the door hinges for Gnd. (Another bad Engineering ideal)
I run an addidtional Gnd wire, with the harness and attach right to the motor from the birdcage.
