Pinpoint Test AC: The Trailer Lamps Are On Continuously

Trailer Lamps

Pinpoint Tests

Pinpoint Test AC: The Trailer Lamps Are On Continuously

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

Normal Operation - Trailer Tow Stop/Turn Lamp

The trailer tow LH stop/turn relay coil receives voltage when the vehicle LH rear stoplamp is illuminated. When the trailer tow LH stop/turn relay is energized, the voltage is routed to the trailer tow connector.

The trailer tow RH stop/turn relay coil receives voltage when the vehicle RH rear stoplamp is illuminated. When the trailer tow RH stop/turn relay is energized, the voltage is routed to the trailer tow connector.

Trailer Tow Parking Lamp

The trailer tow parking lamp relay coil receives voltage when the vehicle parking lamps are illuminated. When the trailer tow parking lamp relay is energized, the voltage is routed to the trailer tow connector.

This pinpoint test is intended to diagnose the following:

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



PINPOINT TEST AC: THE TRAILER LAMPS ARE ON CONTINUOUSLY

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 mounted on the bumper for signs of corrosion or damage. Repair or install a new trailer tow connector as required.

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AC1 CHECK FOR VOLTAGE AT THE TRAILER TOW CONNECTOR


- Ignition ON.
- For the LH trailer stop/turn lamp, measure the voltage between the trailer tow connector LH stop/turn lamp voltage supply pins, circuit CAT06 (YE), component side and ground.




- For the RH trailer stop/turn lamp, measure the voltage between the trailer tow connector RH stop/turn lamp voltage supply pins, circuit CAT09 (GN), component side and ground.




- For the trailer parking lamps, measure the voltage between the trailer tow connector parking lamp voltage supply pins, circuit CAT11 (BN), component side and ground.




- Is any voltage present?

Yes
GO to AC2.

No
The vehicle is operating correctly. SEND the trailer to an authorized camper/trailer repair facility.

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AC2 CHECK THE SUSPECT RELAY


- Ignition OFF.
- Disconnect: Suspect Trailer Tow Relay.
- Carry out the component test for the suspect trailer tow relay.

- Is the trailer tow relay OK?

Yes
REPAIR circuit CAT06 (YE) (LH turn), circuit CAT09 (GN) (RH turn), or circuit CAT11 (BN) (parking lamps) for a short to voltage. TEST the system for normal operation.

No
INSTALL a new trailer tow relay in question. TEST the system for normal operation.

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