Troubleshooting Lighting Function On Trailer Wiring Harnes

Apply the battery negative wire to the ground pin on the trailer s connector.

Troubleshooting lighting function on trailer wiring harnes. If the trailer lights flicker on and off there is a good chance the trailer is grounding by way of the hitch instead of through the trailer s wiring connector. 5 wire trailer wiring diagram. Complete with a color coded trailer wiring diagram for each plug type this guide walks through various trailer wiring installation solution including custom wiring splice in wiring and replacement wiring. Hard wire only vehicle has combined brake and turn signals brake light wire on harness is not grounded.

Clean the connector photo step 2 below and check again. Ground problems are the top cause of issues with trailer wiring. Does 12 volt wire on trailer side 7 way have to be connected if trailer does not need 12 volt power. If your vehicle is not equipped with a working trailer wiring harness there are a number of different solutions to provide the perfect fit for your specific vehicle.

Pay particular attention to all ground connections on both the vehicle and trailer side. Then one circuit at a time apply the battery positive wire to the contacts on the trailer connector. Most likely the ground wire on the trailer is not secured properly. The only point of contact to the outside world meaning the world that exists outside of the trailer itself comes on the truck side of the four prong connector or seven prong connector if you are using a higher end system for trailers with electric.

Harness has been overloaded due to excessive draw from lights or a short in the trailer wiring. Begin by cleaning the ground connections. A trailer wiring system is grounded to the frame near the coupler and each light also needs to be grounded. If there is not a white ground wire coming out of a trailer light then the light is grounded through its mounting studs.

If the white ground wires are not firmly attached to a clean rust and paint free surface there may be an inadequate ground that will not pass enough current for all light functions. If you still have problems make an appointment to have the wiring checked. 5 way trailer wiring diagram allows basic hookup of the trailer and allows using 3 main lighting functions and 1 extra function that depends on the vehicle. If the lights on the tester function properly the problem is the trailer lights or harness and you need to some trailer lights troubleshooting.

For the most part the wiring harness that operates your trailer lights is a closed system. Each component should have its own ground to the frame of the trailer. An extra pin allows using another extra function. Check for broken wires near the connector.

Using one turn signal engages the turn signals on both sides of the trailer. Recommended wiring harness for rewiring a 26 foot gooseneck stock trailer.