What Color Trailer Wires go to the Red, Black and White Taillight Wires

Updated 06/19/2026 | Published 12/16/2020

Question:

So the original wires on trailer are down, yellow and white...... the new pig tail has red, black and white. Which wires go with each other. It’s a turn signal light

asked by: Nana G

Expert Reply:

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 your new light black=taillights, red=turn/brake and white=ground.

You will connect brown to black, yellow to red and white to ground.

expert reply by: Randy B

Tim D.

12/6/2024

You said that the black wire is for tail lights—is the tail light the same as reverse light (which is “on” only when transmission is in the reverse gear)? If so, I want to connect my Apple CarPlay backup camera red wire to the input side black wire of the curt 56040 to switch the CarPlay screen to reverse camera view. Will this work? I assume the input side black wire is 12V when in reverse gear?

Kevin C.

12/6/2024

@TimD The Curt # C56040 is only a 4-pole wire harness and wouldn't have a reverse light wire. You would just need to pull out one of the tail lights and splice your camera's power wire to the wire for your reverse light circuit. I'd use a diode # RM-690 to prevent any feedback from the camera to your tail light.

Iggy

8/1/2025

My reverse light have White - ground Red Black And brown wire I did connected yellow to - red Brown to - brown Red from truck to - black White to -ground Truck is telling me wiring on the trailer is failing How I suppose to connected Soon I connect white to - ground reverse light turn on IM LOST R / Iggy

Robin H.

8/3/2025

@Iggy trace the wires back so you know their functions, the wire colors aren't always what you think they may be and could be non-standard. Once you know which is which you can wire it correctly.

Lisa N.

5/22/2026

@RobinH my old one has two bulbs black red green and white. (Two whites one for each bulb) the license plate holder is broken. I tried an Amazon replacement but it has one bulb and only green and black wires. This is the approx 8 x 5 size. What does Ettailer have for a replacement ?

Wade G.

3/2/2026

In agreement with Randy B, but adding Yellow to Red for LEFT Turn and Green to Red for Right Turn Signal...

David

6/18/2026

On my midwest utility trailer i used a wiring that colors is green and red yellow white and brown on the lights there is white brown and yellow but when matching them I still dont have a turn signal on the left side

Robin H.

6/19/2026

@David you can't always go by the color, they don't always follow the standard. I would trace it back to the function to make sure it is right. If it is and still isn't working, it could also be a bad ground.