How To Connect Electric Trailer Brake Assemblies To Junction Box On Trailer

Updated 06/24/2021 | Published 06/22/2021

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LED Backup Light for Truck or Trailer - Submersible - 10 Diodes - Oval - Clear Lens - Qty 1

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Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot

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Trailer Wiring Junction Box

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Question:

I am trying to find out information about wiring brakes to a utility trailer. I am buying the Prodigy P3 Brake controller and harness for my truck. Im also getting a 7 pin connector with junction box. The idea is once I plug the wire harness into the brake controller and truck I wont have to do anymore wiring to the truck, correct me if Im wrong, I already have the 7 pin outlet on my truck and I think it is wired correctly. My question is, how to wire the brakes from the junction box to the brakes. Are the 10-2-1 duplex the correct wires to go from the junction box to the brakes or is there some other way it should be. Is it that simple, I may be over thinking this but I want to be sure before I start the project. Am I leaving anything out or should this work correctly when I am finish.

asked by: Andrea S

Helpful Expert Reply:

You have a good plan!

You are correct that once you have a functional 7-way connector and the Tekonsha Prodigy P3 # 90195 installed in your truck that you will not need any other wiring on the truck.

Going with a junction box like the # 38656 to install the 7-way connector is the best way as it gives you a very nice location to make all of the wiring connections.

All you will need to do is run the # 10-2-1 like you mentioned from the brake output post on the junction box to one wire on each brake magnet. You will then just ground the other wire on the brake magnets to the frame of your trailer.

If you have not already picked out which wiring harness you are going to install on your truck, just let me know the Year/Make/Model and I would be happy to make a recommendation.

I included a video of the # 38656 being installed for you to take a look at.