Pinpoint Test Y: All The Trailer Lamps Are Inoperative

Trailer Lamps

Pinpoint Test Y: All The Trailer Lamps Are Inoperative

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

Normal Operation

The trailer tow connector receives ground through a dedicated ground circuit. This circuit is the shared ground for all of the trailer lamps.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- Trailer

PINPOINT TEST Y : 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.

Y1 CHECK THE TRAILER TOW GROUND CIRCUITS FOR AN OPEN

- Disconnect: Trailer Tow C439.

- 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) or circuit GD149 (BK/GY) for an open. TEST the system for normal operation.