Connecting a 5-Pin Trailer Wiring Harness for Motorcycle to a Trailer with 4-Way Flat Plug

Updated 01/21/2020 | Published 03/30/2014

Products Featured in This Question

Hopkins Wiring Harness with 5-Pole Flat Trailer Connector - Vehicle End - 5' Long

(17)

$11.72

Hook Probe Circuit Tester

(70)

$13.94

Question:

I purchased a Wiring Harness 51-7907 and installed it on my bike. The problem is this is a 5 wire Harness and the trailer I bought has a 4-way Flat plug on it. Will the converter HM-48895 solve my problem. From what I read I think it will so please let me know for sure.

asked by: Chris T

Expert Reply:

The Hopkins Taillight Converter Kit with 4-Way Flat Connector # HM48895 will work as long as you do not mind having a 4-way connection on your motorcycle. You will have to remove the 5-pin connector and wire the converter on the motorcycle to reduce its 5-wire system to a 4-wire system.

Your trailer should be wired as follows:

White wire = ground
brown = taillight
yellow = left turn and brake
green = right turn and brake

Attach the white ground wire to a suitable ground on the motorcycle chassis. Use a circuit tester like # PTW2993 to find the taillight circuit and attach the brown wire. Next, find the brake signal and attach the red wire to this circuit. Find the left and right turn signal wires and attach the yellow and green wires to these respectively. You will then have a properly functioning 4-Way at the rear of the motorcycle.

expert reply by: Chris O

Ken H.

1/13/2020

i have a honda goldwing with a 5 wire flat plug how do i go to a trailer with a 4 pin flat plug the blue wire on my bike is the brake light ?

Jacob H.

1/21/2020

The blue wire is either going to be a trailer break signal wire (unlikely) or a break light wire that has been split off from the right and left turn signals. I will provide a link to a converter # RM-732 that you can use if it is a brake light wire. It will take the brake light and turn signals and combine them back together for your trailer to receive the correct 4 pole signals.

Helpful Links

Wiring/Roadmaster/RM-732.html