Pinpoint Test T: An Individual Reversing Lamp Is Inoperative

Reversing Lamps

Pinpoint Tests

Pinpoint Test T: An Individual Reversing Lamp Is Inoperative

Refer to Wiring Diagram Set 93, Reversing Lamps for schematic and connector information. Diagrams By Number

Normal Operation

When the reversing lamps relay is energized, voltage is supplied to the reversing lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Rear lamp jumper harness



PINPOINT TEST T: AN INDIVIDUAL REVERSING LAMP IS INOPERATIVE

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

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T1 CHECK FOR VOLTAGE TO THE REVERSING LAMP


- Ignition OFF.
- Disconnect: Inoperative Rear Lamp.
- Apply the parking brake.
- Ignition ON.
- Select REVERSE.
- Measure the voltage between the LH reversing lamp C414-4, circuit 15S-LG9 (GN/BK), harness side and ground; or between the RH reversing lamp C417-4, circuit 15S-LG16 (GN/OG), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to T2.

No
REPAIR circuit 15S-LG9 (GN/BK) (LH reverse lamp) or circuit 15S-LG16 (GN/OG) (RH reverse lamp) for an open. TEST the system for normal operation.

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T2 CHECK FOR VOLTAGE TO THE REVERSING LAMP USING THE CONNECTOR GROUND


- Measure the voltage between the LH reversing lamp C414-4, circuit 15S-LG9 (GN/BK), harness side and the LH reversing lamp C414-5, circuit 31-LF23 (BK), harness side; or between the RH reversing lamp C417-4, circuit 15S-LG16 (GN/OG), harness side and the RH reversing lamp C417-5, circuit 31-LF24 (BK), harness side.




- 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 rear lamp ground circuit for an open. TEST the system for normal operation.

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