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

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Answer 3

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Answer 4

For new leaf springs for your 2019 Grand Design Solitude 5th Wheel you'll need to know the axle capacity and measure the leaf springs to find the correct replacement. I've attached some diagrams below for both double-eye and slipper spring…

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Answer 5

The Blue Ox BX7365 "Alpha" tow bar has been discontinued and was replaced by the #BX7380 "Alpha 2" which includes an improved non-binding system, and now includes safety cables. Otherwise their specifications are the same. Since…

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Answer 6

The Blue Ox Avail Non-Binding Tow Bar #BX7420 and etrailer XHD Non-Binding Tow Bar #e67ZR are fairly similar but have a few key differences. The first difference being the weight capacity, the #e67ZR has an extra 500lbs of capacity over the #BX7420.…

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Answer 7

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 8

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 9

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 10

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 11

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 12

The brown (running light) wires all run to each other as they carry the same circuit. The reason there is two browns on the trailer side is because there are running lights that are on both sides of the trailer. Aside from that all the rest of the…

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