open circuit on driver side power window
Asked by GuruWKB2H May 15, 2018 at 03:24 PM about the 1997 Ford F-150 XLT Extended Cab SB
Question type: Maintenance & Repair
Pulled the switch plugs on driver side and used a test light. On the plug for the driver window one of the contacts lights up without depressing the button. The passenger side works fine. I don't know where to start finding a solution.
4 Answers
Sounds like the drivers side window does not respond to input, but all other windows will operated from master control on drivers side, right? If you unplug the connection for the drivers side window motor, you should be able to test the individual switch with a multi meter connected to the outputs leading to the motor. If there is a fault you will have to replaced the master control switches. Make sure all the other windows operate properly from the master control.
It also depends on how the master switch is wired. A wiring diagram is most helpful. Power could be supplied to the master control through the drivers side switch then routed to the other window controls. The motors used in windows are DC motors. To make them go up or down all that is needed is to reverse the polarity to the motor and it runs in the other direction. The switch accomplishes that function. With the switch in the neutral position, key in on position, not pushed up or backward there should be no voltage output to the motor. A small 12V test light should indicate the problem.
I hear what you're saying but I believe the switch is not the problem because I took another switch from an auto that was working fine and had the same problem. The problem is in the wiring to the plug that plugs into the switch. Test light shows it is hot when the key is on. It is not supposed to be. The switch is what allows juice to operate the window.;
Voltage must be supplied to a switch for it to work, else there is nothing to switch. Try unplugging the connection to the drivers side window and see if the other windows function from the master control. If they don't, then the power supplied via that connection powers the entire master switch.