Ok so im helping my dad on his 94 xlt. We are trying to diagbose ehy his window on the passengers side will go up but not down. We have tested the motor and it works fine botg ways on test leads, and the switch has been replaced. when pressed up, griund and power are supplied to the two wires, but when pressed down it is reversed, but with no ground. It doesnt work on either side (driver or passenger) when pressed down. Any ideas on where the ground iss supplied from or what could be causing this ?

 

See if this might help

 

that definitly cleared up what im looking at haha tank you now i just gotta figure out where that ground is going... im gonna try cleaning and tightening all the contacts again and see if that helps

 

Both switches have to be good, it won't work right if either switch is bad. The polarity is reversed for up and down and the unused switch completes the circuit.

 

Thanks for all the help guys, it turned out to be a worn ground pole on the drivers side switch, so I changed it and cleaned the contacts then threw on some solder with a new switch and pops is back in business! Thanks again guys