Troubleshooting 7-Way Trailer Wiring with Colors That Don't Match Functions

Updated 09/06/2017 | Published 09/03/2017

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

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Question:

I have a Coleman pop up with a seven wire connector . I need a diagram but all the ones I look up have different colors . My wires fro camper side are red, green, blue, teal blue , and two black . Ive tried multiple ways and none work correctly . Please help . It has been suggested to wire by function , how is that done

asked by: Dan

Expert Reply:

Wiring by function is the route to go for your situation. This is done by testing each wire of your trailer individually. The easiest way is to use a 12V battery and connect the negative terminal to the trailer's ground on the frame and then use the positive terminal with a jump wire to connect to each individual wire.

One wire in your 7-way will be the ground wire. You will want to find this one first because it will cause a spark if you connect the battery to it. You can trace the wire attached to the frame to the 7-way connector to see which color it is and where it is located to avoid adding power to that contact point.

Then you can add power to each of the other wires individually to see what function corresponds. The tail light/running light wire will light both sides with red and also a license plate light if you have one.
The reverse lights will light both sides white.
The right turn and stop wire will light the right side only
The left turn and stop wire will light the left side only
The brake controller wire will add braking to your trailer
The 12V power will run to your trailer battery and breakaway system if you have one.

I've attached a photo to help with locations on the trailer side connection as well as the vehicle side connection so you can make connections match. I recommend using the Epicord 7-Way Molded Trailer Plug with Junction Box - 10' Long # 277-000141 along with ring terminals like # 44-5310A to make the connection to the proper locations easy.