Trailer Turn Signals Do Not Work when Running Lights are On

Question

Question:

all lites on trailer work,but when headlights are on,i get no turn signal.turn works on truck,but not on trailer

asked by: Jerry H

1

Helpful Expert Reply:

This sounds like a ground issue. 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.

expert reply by: Michael H

1

Answer 1

Running a separate ground for each light is definitely the best way to wire an LED trailer, so you are definitely doing that properly. The standard wiring is actually a little smaller than 14 gauge, however, and the Optronics #A35W42B will follow…

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Answer 2

Unless ShoreLand'r has a special wiring harness kit that has all of the connectors for your lights (which is very unlikely) you are looking at a complete custom job. You can either choose to replace the damaged wiring that you see with 16 Gauge…

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Answer 3

The longest 4-way harness we offer that has all 16 gauge wire is the Wesbar Harness part #W787274 which is 14 feet long. For one that is 30 feet long that has a 16 gauge ground wire and 18 gauge signal wires you would want the part #W002230.

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Answer 4

The best way to handle the grounds for lights on an aluminum trailer is to mount a junction box like #38656. You can then run ground jumpers from all lights back to the junction box and also connect the 4-pole such as #W787268. The box provide both a…

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Answer 5

I went out to our warehouse and measured a length of 34-1/2 inches for the white ground wire from where it comes out of the back of the 4-Way on the Hopkins Harness #HM48265. The white wire is 16 gauge. I have attached a short video review that you…

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Answer 6

Wiring the grounds for your tail lights and the 35 ft. Wishbone 4-Way Trailer Wiring Harness with 42 inch Ground Wire, item #A35W42B, is fairly simple. The 42 inch ground wire provided with the harness is normally attached to the trailer frame near…

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Answer 7

The gauge of the wiring in the 4-way kit part #A35W42B is 18 gauge.

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Answer 8

It sounds like the trailer has a grounding issue. Grounding problems can cause all sorts weird effects and aluminum trailers are notorious for issues with grounding and can sometimes require ground jumper wires. Often the easiest way to do this is to…

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Answer 9

Most trailer wiring that runs to incandescent trailer lights is 16 gauge which would be a little less than what we would like, However for LED lighting 16 or 18 gauge is fine. To make your project easier I would use the Optronics #A35W42B wiring…

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Answer 10

Aluminum trailer frames or bodies can cause grounding issues so I suggest using a separate ground wire that runs from the rear of the trailer up to the main ground post in the junction box like #38656. You can join the ground wires for the individual…

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Answer 11

I went out to the warehouse and pulled a 35 ft. Wishbone 4-Way Trailer Wiring Harness, #A35W42B, and used a wire gauge tool to measure the wires. The copper wire itself is 20 gauge. If you measure the wire with the insulation on it then it is thicker…

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