I have a '99 Ranger with a driver's side window that will go down but not up. With the window motor disconnected I get +12V and -12V readings at the connector. When I reconnect the motor and take readings I get -12V and 0V. Any ideas?

 

sounds like the motor is toast or the switch is bad

 

I tested the motor and it operates in both directions.

 

then id replace the switch on the panel