Pinpoint Test B: The Instrument Cluster Illumination Is Inoperative

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

B1 CHECK CIRCUIT 29S-LA31 (OG/BU) FOR AN OPEN
- Disconnect: Instrument Cluster C2220.
- With the parking lamps ON, rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the instrument cluster connector C2220-29, circuit 29S-LA31 (OG/BU), harness side and ground.
  
  Fig 1: Checking Circuit 29S-LA31 (OG/BU) For Open
- Is the voltage greater than 10 volts?
Yes : GO to B2.

No : REPAIR the circuit. TEST the system for normal operation.
B2 CHECK CIRCUIT 91-GG14 (BK/OG) FOR AN OPEN
- Turn the parking lamps OFF.
- Measure the resistance between the instrument cluster C2220-30, circuit 91-GG14 (BK/OG), harness side and ground.
  
  Fig 2: Checking Circuit 91-GG14 (BK/OG) For Open
- Is the resistance less than 5 ohms?
Yes : GO to B3.

No : REPAIR the circuit. TEST the system for normal operation.
B3 CHECK FOR CORRECT INSTRUMENT CLUSTER OPERATION
- Disconnect the instrument cluster connector.
- Check for:
  - corrosion
  - pushed-out pins
- Connect the instrument cluster connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes : INSTALL a new instrument cluster. REFER to INSTRUMENT CLUSTER . TEST the system for normal operation.

No : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.