Pinpoint Test C: The Climate Control Panel Illumination Is Inoperative

WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.

C1 VERIFY THE CLIMATE CONTROL ILLUMINATION
- Place the headlamp switch in the PARK position.
- Rotate the instrument panel dimmer switch to the full illumination position.
- Do the climate control illuminations operate correctly?
Yes

System is OK.

No

If the manual climate control illumination does not operate correctly, GO to C2.

If the EATC illumination does not operate correctly, GO to C4.

If the front or rear auxiliary climate control illumination does not operate correctly, GO to C5.
C2 CHECK FOR VOLTAGE ON CIRCUIT 235 (RD/BK)
- Disconnect: Manual Climate Control C294b.
- Measure the voltage between the manual climate control C294b-10, circuit 235 (RD/BK), harness side and ground.
  
  Fig 1: Measuring Voltage Between Manual Climate Control C294b-10, Circuit 235 (RD/BK) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes

GO to C3.

No

REPAIR the circuit. TEST the system for normal operation.
C3 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Measure the resistance between the manual climate control C294b-6, circuit 1205 (BK), harness side and ground.
  
  Fig 2: Measuring Resistance Between Manual Climate Control C294b-6, Circuit 1205 (BK) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes

INSTALL a new manual climate control. Refer to CLIMATE CONTROL SYSTEM . TEST the system for normal operation.

No

REPAIR the circuit. TEST the system for normal operation.
C4 CHECK CIRCUIT 235 (RD/BK) FOR VOLTAGE
- Disconnect: EATC C228a.
- Measure the voltage between the EATC C228a-16, circuit 235 (RD/BK), harness side and ground.
  
  Fig 3: Measuring Voltage Between EATC C228a-16, Circuit 235 (RD/BK) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes

INSTALL a new EATC. Refer to CLIMATE CONTROL SYSTEM .

No

REPAIR the circuit. TEST the system for normal operation.
C5 CHECK AUXILIARY A/C CLIMATE CONTROL CIRCUIT 235 (RD/BK) FOR VOLTAGE
- Disconnect: Front Auxiliary A/C Climate Control C938a.
- Disconnect: Rear Auxiliary A/C Climate Control C940a.
- Measure the voltage between the front auxiliary A/C climate control C938a-6, circuit 235 (RD/BK), harness side and ground; or between the rear auxiliary A/C climate control C940a-6, circuit 235 (RD/BK), harness side and ground.
  
  Fig 4: Checking Auxiliary A/C Climate Control Circuit 235 (RD/BK) For Voltage
  Courtesy of FORD MOTOR CO.
- Are the voltages greater than 10 volts?
Yes

GO to C6.

No

REPAIR the circuit. TEST the system for normal operation.
C6 CHECK AUXILIARY A/C CLIMATE CONTROL CIRCUIT 1205 (BK) FOR AN OPEN
- Measure the resistance between the front auxiliary A/C climate control C938a-9, circuit 1205 (BK), harness side and ground; or between the rear auxiliary A/C climate control C940a-9, circuit 1205 (BK), harness side and ground.
  
  Fig 5: Checking Auxiliary A/C Climate Control Circuit 1205 (BK) For An Open
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes

If front auxiliary A/C climate control, INSTALL a new front auxiliary A/C climate control. Refer to CLIMATE CONTROL SYSTEM .

If rear auxiliary A/C climate control, INSTALL a new rear auxiliary A/C climate control. Refer to CLIMATE CONTROL SYSTEM .

No

REPAIR the circuit. TEST the system for normal operation.