Solution for 4-Way Adapter With 4-Way Flat Male End and 4-Way Round Male End

Updated 06/01/2022 | Published 05/29/2022

Products Featured in This Question

Custer Trailer Connector Adapter - 4-Way Round to 4-Way Flat

(26)

$18.27

Deka Heat Shrink Butt Connector - 16-14 Gauge - Nylon Insulation - Blue - Qty 5

(1148)

$8.64

RoadMaster 4-Wire Connector - Vehicle End

(46)

$9.55

Question:

Hello, I am looking for an adaptor with a flat 4 pin connection actually 3 pins and one hole on the car end and a round 4 pin connection actually 4 pins on the trailer end. I have not been able to find one on line. Can you help me find one? Thank you

asked by: Randy W

Expert Reply:

Your typical 4-way flat to round adapter like the # ADP001 is the opposite of what you need on both ends. Although nobody makes an adapter like this, you can easily make your own. For the 4-way flat trailer end connection you can use the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long # HM38138. You can cut the wiring harness down if you want it to be shorter but this gives you a decent amount of wire to work with.

Then you will need the RoadMaster 4-Wire Connector - Vehicle End # RM-910030-1. You will need to connect the wires from the # HM38138 to the correct pins on the 4-way round connector. Make sure it matches up with your current wiring. I have attached a picture showing the typical wiring for a 4-way round but wiring colors aren't always universal.

The other option you have is to cut off that 4-way round on the trailer side. After you cut it off you can connect the # HM38138 to the wires and plug it into the 4-flat on your vehicle. I recommend using # DW05744-5 to make your connections. This is going to be the simplest solution.

I have attached some review videos along with a helpful article on 4-way wiring for your reference.

expert reply by: Robin H