Standard Color Code for Wiring Simple 4 Wire Trailer Lighting

Question

Question:

I have had to mess with trailer wiring for years, once or twice a year anyway, and I just cannot keep the color code right, ect white/ground, brn/ running lights, grn/ right turn, yellow left turn? Please help me get it right. thanks

asked by: Gary R

0

Expert Reply:

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 connector are as follows with the 4 colors of the 4-way connector remaining the same.

White-Ground
Brown-Tail/Running Lights
Green-Right Turn/Brake - Remember green has an R in it
Yellow-Left Turn/Brake - Remember yellow has an L in it

Blue-Brake Controller Output
Purple-Auxiliary 12v Power/Reverse Lights/Reverse Lockout For Trailer Brakes
Black 12v Battery Power

I have posted a link to our FAQ wiring page for more detailed clarification.

expert reply by: Robert G

0

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Dennis

4/14/2020

I have a separate wire for brake lights. How does that connect into a 4 pin connector?Thanks for any help

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Y

5/24/2020

I don’t have a white wire coming out of my Chevy 2006 pick up. Red black and blue are the three big wires then ther are five other I want to hook up a flat 4 prong hook up to my trailer which wires do I use my trailer connecter has four colors green Brown white and yellow what goes where!!!!

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Chris R.

5/27/2020

You'll need to test the wires coming from your truck individually for function. Use a circuit tester while you have a buddy turn on each of the lights in the cab, locating which wire shows power with each function. You will then be able to match them up to the 4-Way harness. I'm not able to track down a wiring diagram for your Chevy truck.

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Clyde T.

8/24/2024

@ChrisR my problem is I had a yellow wire loos and tried to put it back into the connector and when I did the left turn signal was on but turned the right side blinker on and all lights flashing on 4ways

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Chambers

11/27/2024

@ChrisR help!!! All my lights on my trailer works except for the running lights can a fuse cause this

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Steve

7/25/2020

I have two amber and two red side marker lights for a boat trailer. This is an older 1999 trailer. The existing lights had one wire connected and it’s the brown wire (4-pin) 5 wire. The replacement lights have two wires red and black. I currently only have the brown wire exposed. How do I wire brown wire to this light.

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Chris R.

7/30/2020

You will need to find what functions the red and black wires on the new light are supposed to carry. There should hopefully be a label on the wire itself or at the back of the light housing where they connect. It's possible the black wire is for ground while the red wire is for power (which is what you would connect to the trailer brown wire) but you'll want to try and verify this.

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Shaun M.

10/9/2024

@ChrisR Shaun m the red is probly for brakes I'm not sure what black wire does tho white ground red is stop i c found that out by trial and error but where would you hook the vlalcnone into i gotta make to court this morning battle a new insurance charge for the same vehicle. I'm working on right now. So if anybody could help me. I'd greatly appreciate a text or an email ed as soon as possible please.And thank you

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Bryce D.

10/9/2024

@ShaunM Shaun, I'd suggest using a circuit tester like # PTW2992 to find out what each wire function does.

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Bob O.

8/12/2020

1995 GMC C1500, the OEM trailer harness has all the standard colors plus a lighter green, five total. Can I assume the lighter green is backup lights?

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Jon G.

8/25/2020

That's a safe assumption, but I recommend testing it out with a circuit tester like part # PTW2993 just to be on the safe side of things.

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Leo

7/24/2024

Bob, I have this wiring diagram and colors on my 6 way plug (towed vehicle) and recently purchased brake buddy Part#39332 battery maintainer, what location do I attach the red wire that is attached to the brake buddy part 39332, since the black wire will be attached to the positive terminal of the towed vehicle? Thx for your assistance. Leo

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Charles

11/13/2024

My problem is wiring up the back bottom tail lights of a one ton 2017 Chevy Silverado how is how do the wires connect I'm doing something wrong cuz I'm not getting no lights I have green yellow black and white how do I put them together to make my lights work I need help

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Kate F.

11/13/2024

@Charles Did you set the ground to clean metal surface? I do not have the schematics for the wiring on the 2017 Chevy Silverado, your best bet is going to be to use a circuit tester like # PTW2993 so you can test the wires to figure out the function. If you did not set the ground to a clean metal surface they will not work. Are you referring to the lights on the trailer not working? If so, have you been able to test the lights on the trailer with a different vehicle?

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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…

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Answer 2

It could be a tow package fuse on the vehicle. Use the owners manual to find the locations of fuses/relays related to the tow package wiring to check them and replace as needed. If the issue is not a fuse or relay then you can test the vehicle side…

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Answer 3

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…

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Answer 4

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…

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Answer 5

The best way would be replacing the current 7-way connector at the junction box and installing a longer harness. The junction box should be located not too far behind the coupler of your 2018 Rockwood A-Frame camper and will be on the inside of the…

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Answer 6

There are two options for getting your side marker/running lights wired up on your trailer and I included two diagrams for you to check out. Option A will be to follow one wire that starts at the 4 Flat and follows the trailer frame down one side,…

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Answer 7

I did some research and found that the number you furnished is a gray plastic fender that is for 14 inch tires. We do carry fenders that may work for you. I recommend the Fulton Single Axle Trailer Fender with Top Step, part #F008564. This is a…

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Answer 8

Going by the colors that you mentioned, it sounds like you have the typical set-up, green wire for right turn and brake, white wire for ground, yellow wire for left turn and brake, brown with green wire for right side running lights, and brown with…

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Answer 9

Yes. You will be able to use the Gen-Y Hitch Aluminum Loading Ramp Set - 84" Long x 14" Wide - 6,000 lbs #325-GH-R84 with your 1-3/4" lip. Since the gap between the hook and the ramp is 2 inches, you have enough room. I went ahead and…

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Answer 10

We do! There are a variety of trailer ramp styles and needs out there so we have quite a selection to choose from. For example, we have the 60" x 14-1/2" Aluminum Car Hauler Ramp Set #288-07502 rated for 6,000 lbs, the 84" x 14"…

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Answer 11

The Gen-Y Hitch Aluminum Loading Ramp Sets like part #325-GH-R84 can be used on car hauler trailers with multiple cars per Gen-Y. I have attached the full list of options below.

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Answer 12

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…

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Standard Color Code for Wiring Simple 4 Wire Trailer Lighting

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