Pinpoint Test B: The Auxiliary Climate Control Illumination Is Inoperative: Testing

WARNING: This page is about a different car, the 2005 Mercury Montego, 2005 Ford Freestyle, and 2005 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

B1 CHECK CIRCUIT 2086 (RD/LB) FOR AN OPEN
- Key in OFF position.
- Disconnect: Auxiliary Climate Control C990.
- Key in ON position.
- Measure the voltage between the auxiliary climate control C990-R, circuit 2086 (RD/LB), harness side and ground.
  
  Fig 1: Measuring Voltage Between Auxiliary Climate Control C990-R And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to B2.
- No : REPAIR the circuit. TEST the system for normal operation.
B2 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the auxiliary climate control C990-5, circuit 1205 (BK), harness side and ground.
  
  Fig 2: Measuring Resistance Between Auxiliary Climate Control C990-5 And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : INSTALL a new auxiliary climate control. REFER to AUXILIARY CLIMATE CONTROL . TEST the system for normal operation.
- No : REPAIR the circuit. TEST the system for normal operation.