Pinpoint Test E: The Steering Wheel Switch Illumination Is Inoperative

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

E1 CHECK THE OTHER DIMMABLE LIGHTING SWITCHES
- Ignition OFF.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position and observe other dimmable switches (hazard lamp switch, headlamp switch for example).
- Are all the dimmable switches inoperative?
- Yes: Go to PINPOINT TEST B .
- No: Go to E2 .
E2 CHECK FOR VOLTAGE TO THE CLOCKSPRING
- Place the headlamp switch in the OFF position.
- Depower the Supplemental Restraint System (SRS). Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: Clockspring C218a.
- Connect: Negative Battery Cable.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the clockspring C218a-16, circuit VLN04 (VT/GY) (Navigator) or circuit VLN18 (BU/WH) (Expedition), harness side and ground.
  
  Fig 1: Measuring Voltage Between Clockspring C218A-16, Circuit VLN04 (VT/GY) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: Go to E3 .
- No: REPAIR circuit VLN04 (VT/GY) (Navigator) or circuit VLN18 (BU/WH) (Expedition) for an open. REPOWER the SRS. Refer to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
E3 CHECK FOR VOLTAGE TO THE CLOCKSPRING USING THE CONNECTOR GROUND
- Measure the voltage between the clockspring C218a-16, circuit VLN04 (VT/GY) (Navigator) or circuit VLN18 (BU/WH) (Expedition), harness side and the clockspring C218a-5, circuit GD133 (BK), harness side.
  
  Fig 2: Checking Voltage To Clockspring Using Connector Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: Go to E4 .
- No: REPAIR circuit GD133 (BK) for an open. REPOWER the SRS . Refer to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
E4 CHECK THE CLOCKSPRING FOR AN OPEN
- Remove the driver air bag module. Refer to SUPPLEMENTAL RESTRAINT SYSTEM .
- Disconnect: Upper Clockspring C218b.
- Measure the resistance between the clockspring C218a pin 16, component side and the upper clockspring C218b pin 7, component side.
  
  Fig 3: Measuring Resistance Between Clockspring C218A Pin 16 And Upper Clockspring C218B Pin 7
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the clockspring C218a pin 5, component side and the upper clockspring C218b pin 4, component side.
  
  Fig 4: Measuring Resistance Between Clockspring C218A Pin 5 And Upper Clockspring C218B Pin 4
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes: Go to E5 .
- No: INSTALL a new clockspring. Refer to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.

E5 CHECK THE STEERING WHEEL HARNESS

Disconnect: Steering Wheel Switches.

Measure the resistance between the upper clockspring, harness side, and the steering wheel switch(es) as follows:

RESISTANCE REFERENCE CHART

Upper Clockspring Connector-Pin	Steering Wheel Switch Connector-Pin	Circuit
C218b-7	LH steering wheel switch C2366-4	RD/BK
C218b-7	RH steering wheel switch C2367-6	RD/BK
C218b-4	LH steering wheel switch C2366-3	DG/OG
C218b-4	RH steering wheel switch C2367-1	DG/OG

Fig 5: Checking Steering Wheel Harness (Expedition)

Courtesy of FORD MOTOR CO.

RESISTANCE REFERENCE CHART

Upper Clockspring Connector-Pin	Steering Wheel Switch Connector-Pin	Circuit
C218b-7	LH steering wheel switch C2998-2	RD/BK
C218b-7	RH steering wheel switch C2999-1	RD/BK
C218b-4	LH steering wheel switch C2998-4	DG/OG
C218b-4	RH steering wheel switch C2999-3	DG/OG

Fig 6: Checking Steering Wheel Harness (Navigator)

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes: INSTALL new steering wheel switch(es). Refer to INSTRUMENTATION SYSTEM, MESSAGE CENTER & WARNING CHIMES or DRIVER INFORMATION SYSTEM & ENTERTAINMENT SYSTEM as necessary. INSTALL the driver air bag module.
Refer to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.
No: REPAIR or INSTALL a new steering wheel harness. INSTALL the driver air bag module. Refer to SUPPLEMENTAL RESTRAINT SYSTEM . TEST the system for normal operation.