Pinpoint Test C: The Climate Control Panel Illumination Is Inoperative

C1 DETERMINE THE ILLUMINATION SOURCE
- With the parking lamps ON, rotate the instrument panel dimmer switch to the full illumination position.
- Does the concern involve the A/C switch, recirculating switch or rear window heater switch?
Yes : GO to C2.

No : GO to C5.
C2 CHECK FOR A MULTIPLE LIGHT EMITTING DIODE (LED) OUTAGE
- Observe the A/C switch, recirculating switch and rear window heater switch.
- Do all 3 switches fail to illuminate?
Yes : GO to C3.

No : INSTALL a new climate control panel. TEST the system for normal operation.
C3 CHECK CIRCUIT 29S-LE10 (OG/GN) FOR AN OPEN
- Disconnect: A/C Switch Panel C2263.
- With the parking lamps ON, rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the A/C switch panel C2263-2, circuit 29S-LE10 (OG/GN), harness side and ground.
  
  Fig 1: Checking Circuit 29S-LE10 (OG/GN) For Open
- Is the voltage greater than 10 volts?
Yes : GO to C4.

No : REPAIR the circuit. TEST the system for normal operation.
C4 CHECK CIRCUIT 91-FA13 (BK/OG) FOR AN OPEN
- Turn the parking lamps OFF.
- Measure the resistance between the A/C switch panel C2263-12, circuit 91-FA13 (BK/OG), harness side and ground.
  
  Fig 2: Checking Circuit 91-FA13 (BK/OG) For Open
- Is the resistance less than 5 ohms?
Yes : INSTALL a new climate control panel. TEST the system for normal operation.

No : REPAIR the circuit. TEST the system for normal operation.
C5 CHECK CIRCUIT 29S-LH27 (OG/GN) FOR AN OPEN
- Disconnect: Climate Control Panel C2266.
- With the parking lamps ON, rotate the instrument panel dimmer switch to the full illumination position.
- Measure the voltage between the climate control panel C2266-2, circuit 29S-LH27 (OG/GN), harness side and ground.
  
  Fig 3: Checking Circuit 29S-LH27 (OG/GN) For Open
- Is the voltage greater than 10 volts?
Yes : GO to C6.

No : REPAIR the circuit. TEST the system for normal operation.
C6 CHECK CIRCUIT 31-LH27 (BK) FOR AN OPEN
- Turn the parking lamps OFF.
- Measure the resistance between the climate control panel C2266-1, circuit 31-LH27 (BK), harness side and ground.
  
  Fig 4: Checking Circuit 31-LH27 (BK) For Open
- Is the resistance less than 5 ohms?
Yes : INSTALL a new climate control panel. TEST the system for normal operation.

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