How to Fix Broken Trailer Brake Wiring: A Step-by-Step Guide

When was the last time you did an inspection on your trailer? Do you check for things that are not right? What I mean by that is, do you go physically underneath the trailer, and check your trailer brake wiring?

I did that today and I discovered a major brake fail.

We have electric brakes on our 2021 Grand Design Imagine 2500RL. When I did my inspection underneath the frame, I discovered that there were two wires that were severed, and I can tell that they've been severed for a long time.

It could have been caused by a piece of debris on a road. Who knows? We could have run over a rock piece of wood on the freeway and cut those wires.

I was actually really surprised to see that it happened, but so important to get it fixed. I remember on our trip when I had to hit the brakes a few times, my brakes were skidding. I wonder if it was because only one of the electric brakes on one of the axles was working and the rear axle wasn't working.

Unbeknownst to me, we were probably running our trailer with only one set of trailer brakes. So today we're going to go through how to fix trailer brakes.

Equipment needed for the brake fix

I'm going to use the wire stripper but I don't have my crimpers to crimp the butt connectors with a shrink tube. I also have zip ties to zip tie the wire to the axle, a lighter, and some black electrical tape.

Check trailer brake wiring

As you can see, both a white wire and a green wire are disconnected, plus the zip tie that held the wires to the axle is gone.

Cutting out the metal crimp

First, I need to remove the metal crimp, so I cut it out.

How to wire trailer brakes

Next, I snipped the ends of the wires I want to reattach and then stripped the wire ends.

Crimping the butt connector in place

Once the tip of the wire has been stripped, I feed one end into a butt connector, and crimp it into place so it's nice and snug.

How to fix trailer brakes

Then, I do the same with the green and brown wires. Feed them into the opposite end of the butter connector.

Using a lighter to shrink the butt connector

Take a lighter and hold it up to the butt connector to shrink it. Once it's shrunk, tug on it. Make sure it's nice and strong. 

Wrapping the butt connector in black electrical tape

Now for me, as a little bit of added protection, which I'm always usually overkilling, I like to wrap the butt connector with some black electrical tape.

Then, it's onto the other wires. I just do exactly the same as the first three.

Attaching the brake wiring to the axle

Now it's time to attach the wires to the axle. Got to give enough room for this to move within the confinement of the suspension, but I don't think it's going to move that much. But anyway, let's do a zip tie there. I'm feeling like I want to almost double zip tie, to be honest with you. I'm putting it behind the axle in case a rock hits it.

Testing the trailer brakes

To test the brakes, connect them, lift up the truck with the jack underneath it, spin the tire, and then hit the brakes. Make sure it stops.

How to fix trailer brake wiring

Boom! Brakes are working! That is great news. So where the brakes weren't working, they're working now. That is how you fix your trailer brake wiring.

Let me know if you found this useful in the comments below.

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