Trailer Turn Signals and Brake Lights Not Working when Connected to a 2013 Ram 1500

Updated 11/03/2014 | Published 11/02/2014

Products Featured in This Question

Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector

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$40.63

LCD Digital Circuit Tester

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$28.06

Question:

I own a 2013 Dodge Ram 1500 pick-up truck. The truck has two hook-up options, but I would like to choose the 4-way alternative. I purchased and installed a 4-way harness onto the trailer. After following some basic installation practices, ...I found that the steady/running lights are on when required, but when I tested for the turn signals, brake lights, and four-way emergency flashers, .....there was no change. Nothing else worked. Could I be facing a simple problem, or a multiple of them?

asked by: David

Expert Reply:

Like you have said, the 2013 Ram 1500, if so-equipped, will have both a 7-Way and a 4-Way trailer connector at the back. In order to determine where the problem is you will need to use a circuit tester, # PTW2992, if you do not already have one.

Have someone sit in the truck and go through the light functions while you test the 4-Way with the circuit tester. If everything works on the truck side, then that indicates a problem on the trailer. If the same problem exists on the truck side 4-Way, then there is a problem with the tow package wiring.

If it is the trailer, it could just be a bad ground. Ground problems normally show up when there is more draw on a system such as when you have the running lights on and then use another function like a turn signal or brake light.

Make sure that the vehicle side and trailer side connectors are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces.

The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

If the issue is on the truck side, it could be missing or blown tow package fuses. Use the vehicle owner's manual to find the fuse locations related to the tow package wiring to check them. I have included some links to the right that should help you.

expert reply by: Michael H