its a 88 4runner SR5 and whenever i press down on my window switch it does nothing not even a sound then i press up and it dims the lights on my dash and i can hear it working. I put power directly to the motor and goes up and down. With a Test light i tested the plug that the motor gets power from and used the switch up and down and it seem to get power both ways going up and down. Any other test so i can narrow it down to what it is. Thanks! My passenger window works fine from both switches to.

 

I fought the same problem for months - it's the switch. Took mine apart, tried to diagnose it, cleaned the switches, sometimes it would work, sometimes not... just replace the switch and call it a day!

 

On my 86 pickup the same thing would happen. I would just take the switch out and clean the buildup off. Then it would work again.

 

ill check out the switch more closely tomorrow and see what it is. What is the best way to clean out the switch i've taken it out but haven't really gotten into it.

 

http://www.4crawler.com/4x4/CheapTri...l#WindowSwitch
This may help you.