Pinpoint Test S: An Individual Fog Lamp Is Inoperative

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

S1 CHECK THE FOG LAMP VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Inoperative Fog Lamp.
- Ignition ON.
- Place the headlamp switch in the PARKING LAMPS ON position and engage the fog lamp switch.
- For Escape, measure the voltage between the LH fog lamp C1322-B, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C1323- B, circuit CLF12 (BN/YE), harness side and ground.
  
  Fig 1: Checking Fog Lamp Voltage Supply Circuit For An Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- For Mariner, measure the voltage between the LH fog lamp C152-2, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C162- 2, circuit CLF12 (BN/YE), harness side and ground.
  
  Fig 2: Checking Voltage To Fog Lamps (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: REPAIR circuit GD120 (BK/GN) for an open. TEST the system for normal operation.
- No: REPAIR circuit CLF12 (BN/YE) for an open. TEST the system for normal operation.