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) (Navigator) And VLN18 (BU/WH)
  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 For 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, Component Side 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, Component Side 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:

EXPEDITION

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: Measuring Resistance Between Upper Clockspring Connector C218b, Harness Side, And Steering Wheel Switch Connector C2366/7

Courtesy of FORD MOTOR CO.

NAVIGATOR

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: Measuring Resistance Between Upper Clockspring Connector C218b, Harness Side, And Steering Wheel Switch Connector C2998/9

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?
- Yes : INSTALL new steering wheel switch(es). REFER to INSTRUMENTATION, MESSAGE CENTER, AND WARNING CHIMES or INFORMATION AND ENTERTAINMENT SYSTEMS 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.