Electric Window - NO Power

[lance0802]

1999 Tahoe
Rolled the driver side window down a week ago and then it would not go back up. All of the other windows work fine from their controls and the main driver side control.
Everything up to this point indicated that I had a bad motor. I picked up a new motor yesterday, and decided I would plug it in before installing it just to make sure it worked - it didn't.

I check the voltage with my ohm meter, but I do not get anything when I hit the button. I also tried using my check light - again nothing.

As far as I can tell all of the windows run off of a single 30A fuse, and as I stated above all the other windows work fine.

Not sure where to go from here in diagnosing the problem.

 

[ScottyBoy]

Check all the wires in the door jamb boot to see if any are broken. They might not be so obvious either since the actual wire can break but not the insulation. You will have to meter each wire before and after the jamb and test for continuity. As soon as you find a wire with no continuity, that's your culprit.

 

[_Dylan_]

meter the fuse for power

switch the circuit breakers between the power windows and power locks.

 

[lance0802]

meter the fuse for power

switch the circuit breakers between the power windows and power locks.

12volts at the fuse
Swapped the circuit breakers - nothing changed

Also I am getting 12volts on the backside of the switch when I hit it - both up and down. Problem is somewhere between that point and the motor.

I don't get any power going up or down at the motor.

Is there another relay or something I'm missing? The wires come out of the back of the switch go inside under the kick panel, and from there it becomes very confusing because the wires change colors and then goes back out to the window motor.

 

[ScottyBoy]

The window switch could be bad as well. If the window switch is bad the window sometimes won't even work from the drivers switch.

 

[lance0802]

The window switch could be bad as well. If the window switch is bad the window sometimes won't even work from the drivers switch.

I failed to mention that I swapped out the switch, nothing changed.

 

[GangstaCowboy]

Did it make any grinding noises on the way down? This happened to me one day and the magnet inside the motor broke off and seized it up. Had to replace the whole mechanism.

 

[_Dylan_]

12volts at the fuse
Swapped the circuit breakers - nothing changed

Also I am getting 12volts on the backside of the switch when I hit it - both up and down. Problem is somewhere between that point and the motor.

I don't get any power going up or down at the motor.

Is there another relay or something I'm missing? The wires come out of the back of the switch go inside under the kick panel, and from there it becomes very confusing because the wires change colors and then goes back out to the window motor.

My diagram shows power from the circuit breaker to the convenience center under the dash. Then to the switch, motor, and grounded out after that.

wire colors:
convenience center/fuse box- yellow
into the switch- yellow
out of the switch down- brown
out of the switch up- dark blue
switch ground- black
motor down- brown
motor up- dark blue

I don't see a fuse in the diagram. Just a 20A park lamp fuse for the lights inside the switch.


Check for 12 volts at:
-the circuit breaker
-the yellow pin on the wire plug for the switch
-the pin for the dark blue wire with the switch pressed up
-the pin for the brown wire with the switch pressed down

 

[SunlitComet]

If you have a good fuse and the other windows work and you see the voltage switch on or reverse itself as the button is depressed and a known good motor does not work then you have about a foot of wiring to inspect in the door. The dark blue and brown wire from the switch that feeds the driver window is a direct route. It does not leave the door go somewhere else and then come back.