Pinpoint Test W: All The Trailer Lamps Are Inoperative

Trailer Lamps

Pinpoint Tests

Pinpoint Test W: All the Trailer Lamps Are Inoperative

Refer to Wiring Diagram Set 95, Trailer/Camper Adapter for schematic and connector information. Diagrams By Number

Normal Operation

Ground for all the trailer lamps is provided through circuit RAT08 (WH).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Trailer tow connector
- Trailer



PINPOINT TEST W: ALL THE TRAILER LAMPS ARE INOPERATIVE

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

NOTE: Before beginning diagnostics, visually inspect the trailer tow connector for signs of corrosion or damage. Repair or install a new trailer tow connector as required.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery.

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W1 CHECK CIRCUIT RAT08 (WH) FOR AN OPEN TO THE TRAILER TOW CONNECTOR


- Disconnect the trailer from the vehicle.
- Disconnect: Negative Battery Cable.
- For the 4-pin connector, measure the resistance between the trailer tow C439-4, circuit RAT08 (WH), harness side and ground.




- For the 7-pin connector, measure the resistance between the trailer tow connector pin 2, circuit RAT08 (WH), component side and ground.




- Is the resistance less than 5 ohms?

Yes
The vehicle is operating correctly. SEND the trailer to an authorized camper/trailer repair facility.

No
For the 4-pin connector, REPAIR the circuit. TEST the system for normal operation.

For the 7-pin connector, GO to W2.

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W2 CHECK CIRCUIT RAT08 (WH) FOR AN OPEN


- Disconnect: Trailer Tow C473.
- Measure the resistance between the trailer tow C473-2, circuit RAT08 (WH), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
INSTALL a new trailer tow connector. TEST the system for normal operation.

No
REPAIR the circuit. TEST the system for normal operation.

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