Pinpoint Test I: The Air Inlet Mode 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.

I1 CHECK THE AIR INLET MODE SWITCH ILLUMINATION VOLTAGE CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Air Inlet Mode Switch C2890.
- With the parking lamps on, rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the air inlet mode switch C2890-3, circuit 29S-LH53 (OG/BK), harness side and ground.
  
  Fig 1: Measuring Voltage Between Air Inlet Mode Switch C2890-3, Circuit 29S-LH53 (OG/BK) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: INSTALL a new air inlet mode switch. TEST the system for normal operation.
- No: REPAIR circuit 29S-LH53 (OG/BK) for an open. TEST the system for normal operation.