How to Connect 4-Way to 5-Way Wiring for Cargo Box Tail Lights

Updated 03/07/2023 | Published 03/04/2023

Products Featured in This Question

Tow Ready 4 Pole to 5 Pole Trailer Wiring Adapter

(262)

$18.77

2-to-3 Tail Light Converter for Towed Vehicles w/ Incandescent Tail Lights

(172)

$38.79

5-Flat Trailer End 48" Harness

(42)

$11.40

Question:

I have a 4 flat on my car and I’m trying to hook up a red, white,and yellow LED trailer light but the light has 5wires I tried everything to make it work. I can only get the running lights and the brake lights to work both are red. Sometimes l can get the yellow turn signals to work but then when l step on the brakes the red and yellow lights both come on. I also can’t see any way to get the backup lights to work. I think l need to have a 5 pin connector coming out of the car? I’m lost. Then to top it off the cable l bought has different color wires than the 4flat on the car. I then had to transpose the wire colors. I am installing 2 lights like the one I sent you a picture of. I am installing them on a wooden box that is sitting on my car carrier. I need to have running lights, brake lights and turn signals. The backup light could work but it is not necessary. I have a flat 4 plug on my car.

asked by: Tony

Expert Reply:

I'm happy to help out! The wiring color differences can be a bit frustrating but not all manufacturers use the same colors which is why we always need to match them by function instead - just like what you did.

To get the running, stop, turn, and reverse signals you need the following parts:

4-Way to 5-Way Adapter - # 20036
5-Way Trailer Connector - # 20017
Tail Light Converter - # 118158

This is a cost-effective way to get the functions you're needing. You need to tap into the reverse light circuit on your vehicle with the blue wire on the adapter and then match up the functions from there.

expert reply by: Jon G