Pinpoint Test A: The Ignition Switch Is Inoperative

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

A1 CHECK CIRCUIT SBB14 (BN/RD) FOR VOLTAGE
- Disconnect: Ignition Switch C250.
- Measure the voltage between ignition switch C250-4, circuit SBB14 (BN/RD), harness side and ground.
  
  Fig 1: Checking Circuit SBB14 (BN/RD) For Voltage
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : INSTALL a new ignition switch. REFER to IGNITION SWITCH . TEST the system for normal operation.

No : VERIFY that battery junction box (BJB) fuse 14 (15A) is OK. If OK GO to A2.

If the fuse is not OK, REPAIR the BJB or shorted circuit as necessary. INSTALL a new fuse. TEST the system for normal operation.
A2 CHECK CIRCUIT SBB14 (BN/RD) FOR AN OPEN
- Disconnect: Battery Junction Box (BJB) Fuse 14 (15A).
- Measure the resistance between ignition switch C250-4, circuit SBB14 (BN/RD), harness side and BJB fuse 14 (15A), circuit SBB14 (BN/RD), output side.
  
  Fig 2: Checking Circuit SBB14 (BN/RD) For Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : REPAIR or INSTALL a new BJB. TEST the system for normal operation.

No : REPAIR the circuit. TEST the system for normal operation.