What are the Functions of Trailer Light Green, Yellow, and Brown Wires

Question

Question:

Installing turn lights to a 4 flat trailer. Old original lights have 3 leads, Red, black and green. New Right side wires are Green and brown. New left side wires are yellow and brown. Which colors should be spliced together?

asked by: William I

0

Expert Reply:

Normally, the green wire on the right side carries right turn signal and brake light functions and the brown wire carries running light functions. On the left side, the yellow wire carries left turn and brake lights and the brown wire again carries the running lights. With only 2 wires, these lights must ground through the mounting studs.

Make sure to wire in the new lights by function to the existing trailer wiring and not by color.

expert reply by: Michael H

0

Line C.

5/24/2020

Hi! I only have 3 wires on the trailer (brown, white, green) and 4 on my Chevy van.. extra red.. How do I plug it in ? Thanks!

Chris R.

5/27/2020

The wires on your trailer aren't standard, so I really can't be sure how they would be hooked up to new lights or even up to a 4-Way connector. If the white wire is for ground, you're missing a wire. Is this a new (to you) trailer or are you simply re-wiring the setup? How did the signal lights work before if it's something you've had for a while?

Roger

6/1/2025

Appreciate your help! I’m wiring My boat trailer lights to the usual flat four plug I understand the color arrangements green yellow brown and white. However one wire is green on one side and brown on the other side. Where is it supposed to hook into? I have it with the green it’s that correct? Or brown? Or is it meant for a five flat? Thanks. Roger C ???

Robin H.

6/3/2025

@Roger a 5-way typically has a blue wire that would run to an electric lockout on a brake actuator. Wiring colors aren't always absolute but typically you have green for the right turn/stop and yellow for the left turn/stop with brown for the running lights. Do you have a brown wire instead of the yellow? How many wires are there total? If you have multiple brown wires it is still a 4-way but designed to run down both sides to make hooking up the running lights easier. If you are trying to tie in the existing wires on the trailer to a new 4-way connector I would simply trace the function to figure it out.

Answer 1

Hey Michael! The etrailer Electric Trailer Jack w/ 7-Way #e74GV you were looking at will definitely have enough lift for your Coleman 13R. This is a great option if you just want to power the jack off the 7-way on your vehicle instead of running it…

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Answer 2

It sounds like your trailer tail lights you are using now ground through the mounting hardware. That would be why there are only 2 wires. One of those two wires is going to be for turn signal/brake lights and the other is going to be for running…

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Answer 3

They are single function lights, so they can be used as running lights or stop/turn but not both. So for your trailer to be legal, you will need to run two on each side, one for the running light (brown wire of your 4-way) and one for the turn/stop…

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Answer 4

Hey Chris! The black wire on the etrailer Electric Trailer Jack #e23ZV is just a ground wire. Realistically you can ground it however you want but I would say running it to the frame with a self-tapping screw as indicated in the instructions is the…

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Answer 5

The first thing that I would recommend checking are the ground connections for the trailer side connector and the lights. Poor ground connections are the most common culprit of trailer wiring issues. The lights will have either a ground wire or they…

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Answer 6

Hello Nathaniel, thanks for reaching out. So the etrailer jacks are going to be a great choice from a durability and affordability standpoint. The jacks offer all of the features you would want like a work light, sealed switches and a manual crank…

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Answer 7

We don't have a lot of replacement parts for the Sleeve-Lock A-Frame Trailer Coupler - Flip Latch - Black - 2-5/16 Ball #CA-5296-B that you referenced but we do have the replacement spring part #CA-5196-SPR and the replacement pin #CA-5196-PN.

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Answer 8

Trailer batteries (breakaway or auxiliary) do not have to be charged for the brakes to work with a brake controller when connected to a tow vehicle. You have two isolated problems possibility. A breakaway battery that won't hold it's charge…

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Answer 9

The Sleeve-Lock A-Frame Trailer Coupler part #CA-5296-B is designed for a standard 50 degree a-frame trailer. If you have an a-frame trailer then this is likely what you have as I would say a good 95% of a-frame trailers use the standard 50 degree…

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Answer 10

Hello Kyle, Yes, our etrailer Electric Trailer Jack - A-Frame - 18" Lift - 3,500 lbs #e23ZV would be an excellent fit for your 2-horse trailer at 3,000 pounds. A 4-flat trailer connector only carries lighting functions (tail, turn, brake, and…

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Answer 11

Hey Bob, sorry for the confusion but the overall trailer weight capacity of the Sleeve Lock A Frame Coupler part #CA-5296-B that you referenced is 12,500 lbs and the tongue weight capacity is 1,875 lbs. Tongue weight is the amount of vertical weight…

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Answer 12

Great question, Kevin. Yes, these Lippert ABS 10 inch brake assemblies #LC73PX are designed specifically for 3,500-lb axles that use the Lippert ABS system. For the ABS compatible hub and drum, you'd want to pair them with part #LC44PX. It…

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What are the Functions of Trailer Light Green, Yellow, and Brown Wires

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