Pinpoint Test C: The Ic 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.

C1 CHECK THE INSTRUMENT CLUSTER ILLUMINATION CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: IC C220a.
- With the parking lamps on, rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the IC C220a-24, circuit 29S-GG14 (OG), harness side and ground.
  
  Fig 1: Measuring Voltage Between IC C220A-24, Circuit 29SGG14 (OG) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: GO to C2.
- No: REPAIR circuit 29S-GG14 (OG) for an open. TEST the system for normal operation.
C2 CHECK FOR CORRECT IC OPERATION
- Disconnect the IC connector.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect the IC 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 IC . REFER to INSTRUMENTATION & WARNING CHIMES article. 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.