Pinpoint Test A: The Ignition Switch Is Inoperative

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

A1 CHECK FOR VOLTAGE AT THE CENTRAL JUNCTION BOX (CJB) FUSE 102 (20A)
- Disconnect: CJB Fuse 102 (20A).
- Measure the voltage between the CJB fuse cavity 102, input side and ground.
  
  Fig 1: Measuring Voltage Between CJB Fuse Cavity 102, Input Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to A2.
- No : CHECK the CJB fuse cavity 102 input and output side for looseness, corrosion, dirt, or damage. REPAIR or INSTALL a new CJB as necessary. CLEAR the DTCs. REPEAT the self test.
A2 CHECK CIRCUIT 1050 (LG/VT) FOR VOLTAGE
- Connect: CJB Fuse 102 (20A).
- Disconnect: Ignition Switch C250.
- Measure the voltage between the ignition switch C250-4, circuit 1050 (LG/VT), harness side and ground.
  
  Fig 2: Measuring Voltage Between Ignition Switch C250-4, Circuit 1050 (LG/VT), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to A3.
- No : GO to A4.
A3 CHECK THE IGNITION SWITCH
- Carry out the Ignition Switch Component Test. Refer to COMPONENT TESTING -- F150 PICKUP for component testing.
- Is the ignition switch OK?
- Yes : GO to PINPOINT TEST B .
- No : INSTALL a new ignition switch. REFER to IGNITION SWITCH . CLEAR the DTCs. REPEAT the self test.
A4 CHECK CIRCUIT 1050 (LG/VT) FOR AN OPEN
- Disconnect: CJB C270g.
- Measure the resistance between the ignition switch C250-4, circuit 1050 (LG/VT), harness side and the CJB C270g-4, circuit 1050 (LG/VT), harness side.
  
  Fig 3: Checking Circuit 1050 (LG/VT) For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : INSTALL a new CJB. TEST the system for normal operation.
- No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self test.