Trailer brake issue

[Crooktail]

When under hard braking, my brake controller only shows a maximum of 2 amps going to the trailer brakes. I at first thought that it was the built in brake controller that came with the truck. A few days ago, I moved a friends fifth wheel and under braking, I was showing up to 7 amps on the brake controller. I have now narrowed down the problem to the Montana. My questionis, where do I start looking?

Thanks for any suggestions......

[swanny]

I would start at the plug on the truck that supplies power to the trailer. From there work your way to the brakes. Last year i had an issue with my brakes and it was the splice under the back of the truck. When the dealership spliced all the wire in they used cheap clips and covered them with black tape. So I cut everything off re-spliced with a good butt connectors and then used liquid tape to seal all connections. If your is like mine the light blue wire is the brakes. I also found loose connections at the axles, I cut the underbelly so i could pull some wire and the connections were tucked up over the underbelly.

kevin

[1retired06]

I would start by looking at a resistance issue or poor ground with the brake feed starting from the plug back. As indicated above, the splice at the axle is a weak point to be checked as well.

[dieselguy]

Do you mean volts? A typical magnet on our trailer brakes draws 3 amps when energized. If all four brakes are working correctly, there should be @ 12 amps if you were to put an amp meter around the blue wire going to the trailer. I'm not familiar with the new integrated brake controller on trucks, but the after market ones similar to a Prodigy vary the voltage to the trailer brakes. That's what's displayed on the readout. Voltage increases/decreases the magnets ability to grab at the brake drum. Like mentioned in previous posts ... start at the plug on the back of your truck and work your way back.