Pinpoint Test AH: The Trailer Lamps Are On Continuously

Trailer Lamps

Pinpoint Test AH: The Trailer Lamps Are On Continuously

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

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, 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, voltage is routed to the trailer tow connector.

Trailer Tow Parking

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, 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 AH : 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.

AH1 CHECK FOR VOLTAGE AT THE TRAILER TOW CONNECTOR

- Ignition ON.

- Measure the voltage the between trailer tow connector, harness side and ground as follows:

Connector-Pin Circuit C439-2 CAT06 (YE) C439-1 CAT09 (GN) C439-3 CAT17 (BN)






Is any voltage present?

Yes
GO to AH2.

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

AH2 CHECK THE SUSPECT RELAY

- Ignition OFF.

- Disconnect: Suspect Trailer Tow Relay.

- Ignition ON.

- Measure the voltage the between trailer tow connector, harness side and ground as follows:

Connector-Pin Circuit C439-2 CAT06 (YE) C439-1 CAT09 (GN) C439-3 CAT17 (BN)






Is any voltage present?

Yes
REPAIR circuit CAT06 (YE) (LH turn), circuit CAT09 (GN) (RH turn) or circuit CAT17 (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.