Pinpoint Test G: The Steering Wheel Control Switches Illumination Source Is Inoperative

G1 CHECK THE SPEED CONTROL SYSTEM
- Operate the speed control system.
- Does the speed control system operate correctly?
- Yes : GO to G2.
- No : REFER to SPEED CONTROL to continue diagnosis of the speed control system.
G2 CHECK THE VOLTAGE TO THE CLOCKSPRING CONNECTOR
- Key in OFF position.
- Disconnect: Clockspring C218b.
- Turn the headlamp switch to the parking lamps ON position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the clockspring C218b pin 1, circuit 19 (LB/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Clockspring C218B Pin 1, Circuit 19 (LB/RD), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to G3.
- No : REPAIR circuit 19 (LB/RD). TEST the system for normal operation.
G3 CHECK THE CLOCKSPRING FOR AN OPEN
- Depower the air bag system. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: Top of the Clockspring Connector.
- Measure the resistance between the top of the clockspring connector pin 1, component side and the lower clockspring connector C218b pin 1, component side.
  
  Fig 2: Checking Clockspring For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to G4.
- No : INSTALL a new clockspring. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . REPOWER the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
G4 CHECK THE STEERING WHEEL CONTROL SWITCH HARNESS
- Inspect the steering wheel control switch harness for shorts, opens, or any damage.
- Is the steering wheel control switch harness OK?
- Yes : INSTALL new steering wheel control switch(es). REFER to SPEED CONTROL . REPOWER the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
- No : INSTALL a new steering wheel control switch harness. REPOWER the air bag system. REFER to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.