my drivers window will only go down but not up, it never slowed down it just stopped. when I get home from work I take the door panel off, unplug the motor and test to see if its getting power from the switch. both wires at the motor get power with the switch so I think ok the motor went bad, I replace the motor and its the same thing it will only go down. what am I missing here if both brown and blue wires at th motor are getting volts why will it only go down?

 

Any chance the linkage is frozen/stuck? The motors are on a limit switch and stop when the voltage goes up (stop) I think.

 

no because I tried to run the motor plugged in but not bolted up yet and once I removed the motor I was able to push the window up with no problem. I did do some more testing today and heres what I found the motor seems to run on a reverse negative system, meaning theres only two wires when the up wire gets power the down wire becomes the ground and when the down wire gets the power the up wire is now the ground. if I test the connector unplugged everything is fine but as soon as I put the plug on the motor I get 12ish volts for down and the motor goes down, but with the motor plugged in and I try to put it up I get less then one volt at the motor. everything works fine with the motor unplugged but not when it plugged in

 

it turns out it was the window switch, idk how because everything tested out to be good but the window switch fixed the problem. my doorman window switch was only about a month old but it went bad so i picked up one from the dealer for 20 bucks and all is good now

 

How did you check the switch? I have this same problem.

 

Honestly I didn't and still don't understand how it only worked correctly when it was unplugged from the motor. I did check everything else on the circuit and it all checked out ok. I made the assumption when I was able to jump the switch and get the window to go up. If you do decide to change the switch I would defenitly spend the extra ten bucks for a ac delco switch. The doorman one that was in there was only a few months old and there was a huge deference in the quality between the two

 

Mine had a similar issue, I used electrical cleaner and fix the issue right up.

 

The connection is probably just being made just barely when the switch is operated. Enough contact to show continuity or voltage, but not enough contact to carry current.

I had a brake switch do this to me. Tested fine with a volt meter not connected, but wouldn't work when hooked up in the car

 

exactly