Trailer Brake Lights that Dont Work when Headlights are On
Question:
My turn signals and brake lights work on my trailer except for when I turn my running lights on then only the turn signals work. Everything is properly grounded. As I said everything works just not when the running lights are on.
asked by: Sam
Expert Reply:
It sounds as if there is a weak ground connection somewhere on the trailer. Ground issues normally show up when there is more load on a system. Your situation is a perfect example of that. With the running lights on already drawing power, stepping on the brakes adds even more draw on the system.
First, to isolate the issue, disconnect the trailer from the truck. Then use a circuit tester, like # PTW2993 if you do not already have one, to test the connector on the truck. Have someone run through the functions with and without the headlights on while you test the connector with the circuit tester.
If the issue occurs on the truck without the trailer connected then you will want to look at the ground connection to make sure it is attached to a clean and corrosion free bare metal surface. Also make sure the pins are clean and free of corrosion.
On the trailer side, make sure the main trailer connector ground is attached to a clean metal surface and clean out the connector to get rid or dirt and corrosion. You will also need to make sure the ground for each light is attached to a clean bare metal surface.
If the trailer has an aluminum frame, tilt bed, or folding tongue you will want to run jumper ground wires from each light to the main trailer connector ground. I have included a link to our FAQ article on wiring for you.
Products Referenced in This Question
Product Page this Question was Asked From
- Trailer Wiring
- Trailer Connectors
- Trailer End Connector
- 0 - 5 Feet Long
- Plug and Lead
- 4 Flat
- Draw-Tite
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