Pinpoint Test R: The Individual Reversing Lamp Is Inoperative

WARNING: This page is about a different car, the 2007 Ford Ranger. However, it is still accessible from the selected car via links, so may be relevant.

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

R1 CHECK CIRCUIT GD121 (BK/YE) FOR AN OPEN
- Key in OFF position.
- Disconnect: Inoperative Reversing Lamp
- Measure the resistance between the LH reversing lamp C451-1, circuit GD121 (BK/YE), harness side and ground; or between the RH reversing lamp C461-1, circuit GD121 (BK/YE), harness side and ground.
  
  Fig 1: Measuring Resistance Between LH Reversing Lamp C451-1, GD121 (BK/YE), Harness Side & Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
1. YES : REPAIR circuit GD121 (BK/YE). TEST the system for normal operation.
2. NO : REPAIR circuit CET41 (BN/YE) for an open. TEST the system for normal operation.