Pinpoint Test B: A Single Power Window Is Inoperative-LH Front Window

WARNING: This page is about a different car, the 2006 Mercury Mariner and 2006 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

B1 CHECK THE POWER WINDOW DOWN OPERATION
- Key in OFF position.
- Disconnect: LH Front Window Motor C524.
- Key in ON position.
- While operating the LH front window control switch, measure the voltage between LH front window motor C524-b, circuit 992 (WH/BK), harness side and LH front window motor C524-a, circuit 903 (RD), harness side.
  
  Fig 1: Checking Power Window Down Operation
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts while operating the LH front window control switch in the down direction?
Yes : INSTALL a new window regulator and motor. REFER to WINDOW REGULATOR - FRONT DOOR in this article. TEST the system for normal operation.

No : GO to B2.
B2 CHECK CIRCUITS 992 (WH/BK) AND 903 (RD) FOR AN OPEN
- Key in OFF position.
- Disconnect: LH Front Window Control Switch C508.
- Measure the resistance between LH front window control switch C508-4, circuit 992 (WH/BK), harness side, and LH front window motor C524-b, circuit 992 (WH/BK), harness side; and between LH front window control switch C508-9, circuit 903 (RD), harness side, and LH front window motor C524-a, circuit 903 (RD), harness side.
  
  Fig 2: Checking Circuits 992 (WH/BK) And 903 (RD) For An Open
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : INSTALL a new LH front window control switch. REFER to WINDOW CONTROL SWITCH in this article. TEST the system for normal operation.

No : REPAIR the circuit(s) in question. TEST the system for normal operation.