Pinpoint Test B: Single Power Window Is Inoperative - Driver Front Window

WARNING: This page is about a different car, the 2005 Mercury Mountaineer, 2005 Ford Explorer, 2004 Mercury Mountaineer, and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

B1 CHECK ALL POWER WINDOW OPERATION
- Check the operation of all windows.
- Do all other power windows operate correctly?
- Yes : GO to B2.
- No : REPAIR the power window supply circuit.
B2 CHECK THE DRIVER POWER WINDOW DOWN OPERATION
- Key in OFF position.
- Disconnect: Driver Window Control Switch C504a.
- Connect a jumper wire between driver window control switch C504a-8, circuit 992 (WH/BK), and ground; and between driver window control switch C504a-7, circuit 991 (TN/LB), and the positive battery terminal.
  
  Fig 1: Checking Driver Power Window Down Operation
  Courtesy of FORD MOTOR CO.
- Does the driver power window go down?
- Yes : GO to B3.
- No : REMOVE the jumper wires. GO to B4.
B3 CHECK THE DRIVER POWER WINDOW UP OPERATION
- Connect a jumper wire between driver window control switch C504a-7, circuit 991 (TN/LB) and ground; and between driver window control switch 504a-8, circuit 992 (WH/BK) and the positive battery terminal.
  
  Fig 2: Checking Driver Power Window Up Operation
  Courtesy of FORD MOTOR CO.
- Does the driver power window go up?
- Yes INSTALL a new window control switch. REFER to WINDOW CONTROL SWITCH . TEST the system for normal operation.
- No : REMOVE the jumper wires. GO to B4.
B4 CHECK CIRCUIT 991 (TN/LB) FOR OPEN
- Disconnect: Driver Power Window Motor C524.
- Measure the resistance between driver power window motor C524-2, circuit 991 (TN/LB), and driver window control switch C504a-7, circuit 991 (TN/LB) harness side.
  
  Fig 3: Checking Circuit 991 (TN/LB) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to B5.
- No : REPAIR the circuit. TEST the system for normal operation.
B5 CHECK CIRCUIT 992 (WH/BK) FOR OPEN
- Measure the resistance between driver power window motor C524-1, circuit 992 (WH/BK), and driver window control switch C504a-8, circuit 992 (WH/BK) harness side.
  
  Fig 4: Checking Circuit 992 (WH/BK) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : INSTALL a new driver power window motor. REFER to FRONT DOOR GLASS, FRAMES AND MECHANISMS - EXPLODED VIEW and FRONT DOOR WINDOW REGULATOR MOTOR . TEST the system for normal operation.
- No : REPAIR the circuit. TEST the system for normal operation.