Hi, like the above poster, I have made a living fixing electrical parts on cars. As for power windows, I would first try the window switch while looking at a dome light. If the dome light gets slightly dimmer when you push on the switch, it is most likely a bad motor. If the light only dims in one direction, you have a bad switch. A bad motor will sometimes work if hit with a hammer, but this doesn't fix it, it will still most likely need to be replaced. If you can hear the motor running, but the window doesn't move, it could be stripped gears. If the window regulator looks like an "X" try to get the window all the way in the up position and remove the motor in the door. If you remove the regulator with the motor attached and try to remove the motor from the regulator you can get badly hurt. There is a strong spring that will make this regulator snap like a pair of scissors. This happens when you remove the motor from the regulator. If your window regulator has a tape or cable drive, in most cases, you have to replace the whole thing as a unit. GOOD LUCK.