How to Troubleshoot a Tail Lamp Malfunction on a 16 foot Trailer Pulled by a 2005 Jeep Cherokee

Question:

All the lights work on my 16 trailer stop,turn signals,hazzards but no tail lamps. Its a 4 pole plug coming from my 05 Grand Cherokee and a 4 pole reciever on the trailer. Is it not the right wiring harness? so confused,

asked by: Jarrod

Expert Reply:

It sounds like there is a short in the tail light circuit, which is the brown wire in the 4-way trailer harness.

Using a circuit tester like part # PTW2993, I would check the brown wire on the 4-way connector at the back of your vehicle for voltage while the running lights are being used on your tow vehicle.

If their is voltage present it would be safe to assume that problem is in the wiring of your trailer. If this is the case you will need to inspect the wiring that is on your trailer for any obvious signs of damage.

If their is no voltage present at your vehicles 4-way you will need to check the wiring of your vehicles trailer harness looking for obvious signs of wear or damage.

You should also check that the ground (white) wire is secure and undamaged on your trailer.

expert reply by: Jameson C