Pinpoint Test D: The Audio Unit 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.

D1 CHECK CIRCUIT 29S-LK34 (OG/BK) FOR AN OPEN
- Key in OFF position.
- Disconnect: Audio Unit C2188a.
- With the parking lamps ON, rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the audio unit C2188a-3, circuit 29S-LK34 (OG/BK), harness side and ground.
  
  Fig 1: Checking Circuit 29S-LK34 (OG/BK) For Open
- Is the voltage greater than 10 volts?
Yes : GO to D2.

No : REPAIR the circuit. TEST the system for normal operation.
D2 CHECK CIRCUIT 31-MD34 (BK) FOR AN OPEN
- Turn the parking lamps OFF.
- Measure the resistance between the audio unit C2188a-4, circuit 31-MD34 (BK), harness side and ground.
  
  Fig 2: Checking Circuit 31-MD34 (BK) For Open
- Is the resistance less than 5 ohms?
Yes : REMOVE the audio unit. REFER to INFORMATION AND ENTERTAINMENT SYSTEM . SEND it to an authorized audio system repair facility. TEST the system for normal operation after the repair.

No : REPAIR the circuit. TEST the system for normal operation.