I have a 89 mustang gt vert. I bought the car about 3 months ago and have figured out most of the problems with the car but one is mind boggling. When i bought the car, the passenger side window would go down but not up, so I pulled apart the motor and seen that the gear was broken. So I replaced it, put it back together ,and still it didnt work going up. The next step that I took was to replace the motor, still didnt work. Then the passenger side switch went bad. When I replaced it, the motor would go up real slow, and if I hit the drivers side switch at the same time the window would go up normal. But hitting the drivers side alone would do nothing. So next was the drivers side switch. Now when using the drivers side switch, the passenger side window goes up and down perfect, but using the passnger side switch the window goes down normal and up real slow. Also it drags the engine rpm down like there is a huge load on the alternator. So what the crap is going on. I understand that a wire is most likely shorted or half broken not allowing enough power to the motor, but I do not know which wire it could be. I suck at the electrical side of a car. And I am thinking that I am going to have to take it to a "real" mechanic. Also the lock/unlock button does not work all of the time, but I think that it might be on a different system. Thank you all for your time and I hope one of you have the answer.