How Do Utility Trailer Lights Wire Up to the Trailer Wiring Harness.

Question

Question:

My new lights on trailer has black an red , I need to know witch colors go to red and what to black ? My harness has brown , green , yellow , white

asked by: Ken S

0

Expert Reply:

The red wire is the turn signal wire and will be run to the green wire of your harness if its the right turn signal side, and the black wire will run to the brown wire of your harness. The yellow wire from your harness will run to the left turn signal red wire. The brown wire will also run to the black wire of this light also.

I attached an FAQ on trailer wiring for you to check out also.

expert reply by: Jameson C

0

Bob8

2/12/2020

2 wires both green from trailer. 1 green and 1 black wire on new tail light. How to hook up?

Jacob H.

2/14/2020

The best way to handle this would be to test your wires on your trailer and see which green wire is doing what. I recommend marking them with a piece of electrical tap to know the difference for future reference. You can then hook your light wires up to a 12V battery and see what functions work with the wires.

Graham

2/2/2021

Hi I hope you can help me on the one as I'm trying to connect new lights on my boat trailer and dont know what wire to connect to what wire The trailer has a yellow brown white and red wire while the LED light has a red white green brown and brown and white wire what connects to what

Jon G.

2/2/2021

@Graham Trailer wiring colors can vary from application to application. Your best bet is to figure out which wire carries what function on your trailer wiring and then connect the corresponding wires from your LED lights correctly. You can accomplish this by hooking your trailer up to your tow vehicle and then using a circuit tester to test the wires while you run through the various light functions.

John B.

6/6/2020

I need 2 know how 2 wire a 4 flat on a 2002 chevy tahoe for my trailer Thank u for yas time

Amanda C.

6/14/2020

I have a tail light with a red wire, and a trailer with a green, brown, yellow, and white wire. Where would I attach the red wire to? I thought I would attach it to the brown wire since my brown wire is my light function wire but when I attached it on my tail light did not work. I need help asap!

Chris R.

6/18/2020

Are there any other wires coming from the tail light? It's hard to go just by color alone because not all light assemblies use the same schematic. The brown wire on your trailer would be for running lights.

Answer 1

It is likely that the red wire on your old lights is the turn signal/brake light wire, and the black wire is the running light wire. That would make the white wire the ground. You can verify this by testing the wires using a circuit tester such as…

view full answer...

Answer 2

This is a common question we get on lights like the LED Trailer Tail Light with License Bracket part #328-003-81LBM1. The original colors you have are the traditional trailer wiring code so brown=taillights, red=turn/brake and white is ground. On…

view full answer...

Answer 3

Red, black, and white wires are common on many tail light assemblies. When this is the case, you will have red as stop and turn, black as running light, and white as ground. So you will connect yellow to red on one side of the trailer and green to…

view full answer...

Answer 4

In regards to the 4-way wiring harness you are trying to install; the white wire is for the ground, the brown wire is for the running lights, the yellow wire is for the left turn/brake light, and the green wire is for the right turn/brake light.…

view full answer...

Answer 5

You have it right so far, the 4-way connector is just as you have stated. Remember that Yellow has a L in it so that is the left side brake/turn signal and green has a R in it so that is the right side brake/turn signal. The colors for wiring a 7-way…

view full answer...

Answer 6

Most likely the colors would match with the exception of the red wire on the trailer going to the white wire on the truck. The white wire is the ground circuit so you can trace the RED wire on the TRAILER to see if it attaches to a metal surface on…

view full answer...

Answer 7

Tekonsha Prodigy P2 trailer brake controller, #90885, connects to a fused power source directly to the battery and not an ignition source. This means the controller draws power even with the key off. However, it goes into a kind of sleep mode after…

view full answer...

Answer 8

First you will want to check the wiring of the Hopking Breakaway #20099. If the black wire from the breakaway box is not receiving 12 volts from the 7-way on your tow vehicle it will charge the battery. You will want to use a circuit tester like part…

view full answer...

Answer 9

The P3 brake controller, #90195, will go into a sort of sleep mode after it detects no movement for 15 minutes. While it is on it does not draw very much power. What you can do to make sure it goes to sleep is exit the truck after turning it off,…

view full answer...

Answer 10

A standard trailer breakaway switch like #3802348 does not have a circuit board but a unit like the Tekonsha Trailer BreakAway Kit #PS50-85-320 does have circuit board for its battery tester. If this circuit board is corroded, you need to replace the…

view full answer...

Answer 11

Actually, the P3 now has the upgraded axis accelerometer like the P2. The Tekonsha P3 Trailer Brake Controller #90195, will work with both electric over hydraulic brakes on the trailer as well as electric brakes. It has a menu option on the display…

view full answer...

Answer 12

The Prodigy brake controllers like the P2 part #90885 and the P3 part #90195 are widely considered to be the most reliable around and ironically the Hopkins are considered by many to be the worst. So the fact your Hopkins is working more reliably is…

view full answer...