Installing Replacement 7-Way Trailer Plug on Trailer with 5 Wires

Updated 10/24/2016 | Published 10/21/2016

Products Featured in This Question

Pollak Replacement 7-Pole, RV-Style Trailer Connector Socket - Vehicle End

(708)

$16.13

Trailer Wiring Junction Box

(814)

$27.58

Ring Terminal - 12-10 Gauge Wire - 3/16" Ring ID

(67)

$1.49

Hopkins 7-Way RV Style Connector with Molded Cable - Trailer End - 8' Long - RV Standard

(907)

$46.90

Question:

I have a trailor that has 5 wires running from colors are black white green brown yellow they were connected to a 7 pin connector not working well so I took it apart and before I could see where there wire were connected they pulled lose Ive searched an played with them till Im blue in the face can anyone help

asked by: Mark T

Expert Reply:

We can help you reinstall a working 7-way plug on your trailer.

The easiest way to wire in a new 7-way RV-style plug like # H20046 on your trailer is to use a wiring junction box like # 38656. A junction box will allow you to make the wiring connections using ring terminals like # 44-5310A (for 10- and 12-gauge wires) and # DW05702-1 (for 14- and 16-gauge wires). It also makes it easy to replace the plug if it ever becomes damaged or corroded.

You'll want to test the wires on the trailer (using a 12V battery) to confirm the function carried on each wire. Wire colors are not uniformly standardized for trailer functions so it is best to test before making your connections. Apply 12V power one at a time to each circuit to see what light function activates; then you can make your junction box connections.

The linked article shows you the most common wiring configurations for 7-way connectors and the page for 7-way plug # H20046 indicates the function on each wire in that plug.