Pinpoint Test A: The Ignition Switch Is Inoperative

WARNING: This page is about a different car, the 2007 Ford Pickup, 2007 Ford F550 Super Duty, 2007 Ford F450 Super Duty, and 2007 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.

CAUTION: Use the flex probe kit for all test connections to prevent damage to the wiring terminals. Do not use standard multimeter probes.

A1 CHECK THE VOLTAGE TO THE IGNITION SWITCH
- Key in OFF position.
- Disconnect: Ignition Switch C250
- Measure the voltage between ground and:
  - ignition switch C250-7, circuit 37 (YE), harness side.
  - ignition switch C250-12, circuit 37 (YE), harness side.
  - ignition switch C250-2, circuit 325 (DB/OG), harness side.
  - ignition switch C250-9, circuit 1050 (LG/VT), harness side.
  Fig 1: Checking Voltage Supply To Ignition Switch
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
1. YES : INSTALL a new ignition switch. REFER to Ignition Switch in this article. TEST the system for normal operation.
2. NO : Verify that CJB fuse 103 (30A) is OK. If OK, REPAIR circuit 1050 (LG/VT).
  Verify that CJB fuse 116 (30A) is OK. If OK, REPAIR circuit 325 (DB/OG).
  
  Verify that CJB fuse 110 (30A) is OK. If OK, REPAIR circuit 37 (YE).
  
  TEST the system for normal operation.