Pinpoint Test U: All The Trailer Lamps Are Inoperative

Trailer Lamps

Pinpoint Tests

Pinpoint Test U: 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

The trailer tow connector is provided a single ground circuit for the trailer lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Trailer

PINPOINT TEST U: 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: Failure to disconnect the battery when instructed will result in false resistance readings. Refer to Battery, Mounting and Cables Battery Disconnect.

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U1 CHECK THE TRAILER TOW GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the trailer tow C439-4, circuit RAT08 (WH), harness 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
REPAIR circuit RAT08 (WH) for an open. TEST the system for normal operation.

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