Pinpoint Test Ac: An Individual Reversing Lamp Is Inoperative

WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. 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.

NOTE: Make sure the stoplamps operate before diagnosing the reversing lamps.

AC1 CHECK FOR VOLTAGE TO THE REVERSING LAMP
- Ignition OFF.
- Apply the parking brake.
- Disconnect: Inoperative Reversing Lamp.
- Ignition ON.
- Select REVERSE.
- For Edge, measure the voltage between the LH reversing lamp C414-5 , circuit CLS28 (BU/WH), harness side and ground; or between the RH reversing lamp C417-5 , circuit CLS28 (BU/WH), harness side and ground.
  
  Fig 1: Measuring Voltage Between LH Reversing Lamp C414-5, Circuit CLS28 (BU/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- For MKX, measure the voltage between the LH reversing lamp C414-4 , circuit CLS28 (BU/WH), harness side and ground; or between the RH reversing lamp C417-4 , circuit CLS28 (BU/WH), harness side and ground.
  
  Fig 2: Measuring Voltage Between LH Reversing Lamp C414-4, Circuit CLS28 (BU/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?
- Yes : REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.
- No : REPAIR circuit CLS28 (BU/WH) for an open. TEST the system for normal operation.