Pinpoint Test A: THE IGNITION SWITCH IS INOPERATIVE

WARNING: This page is about a different car, the 2005 Lincoln LS. 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 IGNITION SWITCH
- Carry out the Ignition Switch Component Test. Refer to COMPONENT TESTING for component testing.
- Is the ignition switch OK?
- Yes : GO to A2.
- No : INSTALL a new ignition switch. TEST the system for normal operation.
A2 CHECK CIRCUITS 30-BB20 (RD) AND 30-BB9 (RD) FOR VOLTAGE
- Key in OFF position.
- Disconnect: Ignition Switch C250.
- Measure the voltage between ignition switch C250-7, circuit 30-BB20 (RD), harness side and ground; and between ignition switch C250-1, circuit 30-BB9 (RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Ignition Switch C250-7, Circuit 30-BB20, Harness Side And Ground; And Between Ignition Switch C250-1, Circuit 30-BB9, Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
- Yes : CHECK the instrument cluster for faults. REFER to INSTRUMENT CLUSTER .
- No : REPAIR the affected circuit(s). TEST the system for normal operation.