Pinpoint Test A: All Door Locks Are Inoperative From One Switch

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

A1 CHECK THE SUPPLY VOLTAGE TO THE DOOR LOCK CONTROL SWITCH
- Key in OFF position.
- Disconnect: Inoperative Door Lock Control Switch Connector.
- If the door locks are inoperative from the LH door lock control switch, measure the voltage between the LH door lock control switch C508-3, circuit 517 (BK/WH), harness side and ground.
  
  Fig 1: Measuring Voltage Between LH Door Lock Control Switch And Ground
  Courtesy of FORD MOTOR CO.
- If the door locks are inoperative from the RH door lock control switch, measure the voltage between the RH door lock control switch C629-8, circuit 517 (BK/WH), harness side and ground.
  
  Fig 2: Measuring Voltage Between RH Door Lock Control Switch And Ground
  Courtesy of FORD MOTOR CO.
- If the door locks are inoperative from the rear door lock control switch, measure the voltage between the rear door lock control switch C4121-3, circuit 517 (BK/WH), harness side and ground.
  
  Fig 3: Measuring Voltage Between Rear Door Lock Control Switch And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : INSTALL a new door lock control switch as necessary. TEST the system for normal operation.
- No : REPAIR the circuit. TEST the system for normal operation.