How to Wire the GloLight LED Trailer Tail Light Part # STL178RB to a Trailer Connector

Published 09/20/2018

Products Featured in This Question

GloLight LED Trailer Light w/ Flange - Brake, Tail, Turn - Submersible - Surface Mount - Oval - Red

(95)

$22.68

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

(172)

$38.14

Hopkins Quick-Lock Diode for Towed Vehicles - Qty 1

(6)

$9.96

Quick Fix (TM) 4 Pole Flat Trailer End

(80)

$8.41

Digital Multimeter with 42" Long Test Leads - LED Display

(3)

$22.17

Roadmaster Single Park Light Diode

(120)

$22.21

Wesbar 4-Pole Flat Connector w/ Jacketed Cable - Trailer End - 4' Long

(155)

$15.67

Question:

First, thanks for all of the good info that you provided. I have three more things and that should be it for me. For the Hopkins Quick-Lock Diode part # HM56306 , you said that I would need two of them. I am wiring just one STL178RB light to have both stop/turn signals work with it. Couldnt the two stop/turn signal wires from the trailer connector harness go into the two Hopkins diode inputs and have the one output go to just the one light? The light only has one stop/turn wire. Would that work or would I still need two Hopkins diodes? Do you have the dimensions of the Roadmaster Single Park Light Diode part # RM-690? I couldnt find it on the part page. For the Ram LED Lighted Trailer Hitch Cover part # RP86531, there is a foaminch thing that goes around where it attaches to the hitch. I had one of those foaminch things for a novelty hitch item that I had before and it helps keep water out of the hitch and with vibration. Can that be purchased separately?

asked by: John

Helpful Expert Reply:

The white wire on the back of the GloLight LED Trailer Tail Light part # STL178RB is for the ground. If you were wiring it to a trailer connector like part # HMC20031 then you would just need to make sure that it is attached to the ground terminal and no additional grounds would be needed. The outer ring of the light that you are referring to is made of plastic just like the body of the light is. The wire leads are around 6" long.

I have attached a review video for you.

expert reply by: Conner L

click to enlarge

John

9/18/2018

Conner L.

9/18/2018

In order to have the GloLight LED Trailer Tail Light part # STL178RB illuminate for both the right and left hand turn signals in addition to the brake lights you would need to install a 4-way like the Wesbar 4-Pole Flat Connector part # W787264 on the light in addition to two single diodes like part # RM-690. The diode would be needed so that the right and left hand turn signals do not backfeed into the vehicle wiring as you mentioned. I have attached a diagram which shows you how the light will need to be wired. If you don't want the light to illuminate with the brake lights then a converter box like part # 118158 would also be needed.

John

9/19/2018

I have a couple additional questions. Your picture shows two RM-690s. They look small in your picture, but look much bigger in itsfoot actual pictures. This would be problem with the STL178RB light being so close to the hitch. Is there something smaller that can be used? How about the Hopkins Quick-Lock Diode HM56306 where both turn signals wires coming from the trailer hitch harness connector being used as input and the one output going to the light? Also, there is a box used in the Ram LED Lighted Trailer Hitch Cover RP86531. Is something like that available? Is there a way to tell if the diode is actually working? Thanks!

Conner L.

9/19/2018

The Hopkins Quick-Lock Diode part # HM56306 can indeed be used in place of the Roadmaster Single Park Light Diode part # RM-690. The Hopkins diode measures 1-3/4" long x 3/4" wide. There is only one output on the Hopkins diode so you would need to use one for each turn signal wire. The electrical box on the Ram LED Lighted Trailer Hitch Cover part # RP86531 is not offered separately though I am sure you could modify this unit to work with your light. In order to test a diode you would need a multimeter like part # PT89ZR with a resistance mode.