Pinpoint Test W: An Individual Reversing Lamp Is Inoperative

Reversing Lamps

Pinpoint Tests

Pinpoint Test W: 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 routed to the reversing lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Bulb holder



PINPOINT TEST W: 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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W1 CHECK FOR VOLTAGE TO THE INOPERATIVE REVERSING LAMP


- Ignition OFF.
- Disconnect: Inoperative Reversing Lamp.
- Apply the parking brake.
- Ignition ON.
- Select REVERSE.
- For Styleside, measure the voltage between the LH reversing lamp C487-1, circuit CAT16 (GY/BN), harness side and ground; or between the RH reversing lamp C488-1, circuit CAT16 (GY/BN), harness side and ground.




- For Flareside, measure the voltage between the LH reversing lamp C451-3, circuit CAT16 (GY/BN), harness side and ground; or between the RH reversing lamp C461-3, circuit CAT16 (GY/BN), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to W2.

No
REPAIR circuit CAT16 (GY/BN). TEST the system for normal operation.

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W2 CHECK FOR VOLTAGE TO THE INOPERATIVE REVERSING LAMP USING THE CONNECTOR GROUND


- For Styleside, measure the voltage between the LH reversing lamp C487-1, circuit CAT16 (GY/BN), harness side and the LH reversing lamp C487-2, circuit GD120 (BK/GN), harness side; or between the RH reversing lamp C488-1, circuit CAT16 (GY/BN), harness side and the RH reversing lamp C488-2, circuit GD120 (BK/GN), harness side.




- For Flareside, measure the voltage between the LH reversing lamp C451-3, circuit CAT16 (GY/BN), harness side and the LH reversing lamp C451-1, circuit GD120 (BK/GN), harness side; or between the RH reversing lamp C461-3, circuit CAT16 (GY/BN), harness side and the RH reversing lamp C461-1, circuit GD120 (BK/GN), harness side.




- Is the voltage greater than 10 volts?

Yes
INSTALL a new bulb holder. TEST the system for normal operation.

No
REPAIR circuit GD120 (BK/GN) for an open. TEST the system for normal operation.

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