Normally this would be a simple task, but this isn't exactly going to be a normal set up.

So here's situation.

I recently bought a used 14k dump trailer. The hydraulic motor for the dump trailer is powered directly off of a car battery on the trailer. The battery is recharged directly from the 12v aux pin on my 7 way trailer connector with an inline fuse.

I have a second flat bed trailer for hauling vehicles that I'm going to be adding a 13.5k lb winch to next summer. I'm going to be installing wiring in the truck to supply up to 350 amps to the winch on this trailer. The hot wire will be protected by a resetting circuit breaker and the circuit will be controlled via relay from the cab. The relay is only intended to be closed when power is needed to run the winch or dump trailer.

I would like to use this opportunity to add additional wiring to the dump trailer so I can run its hydraulic motor directly from the truck, from the same plug and provide the means to charge the battery faster.

Here's my question.

What do you guys think the best way to do this is?

I considered adding a dc/dc charger powered via the aux pin in the 7 way, but I am slightly concerned about any unwanted current flowing back through the high current wiring into the starting and charging circuit. I'm not sure if I should be worried, I'm just aware of it being a potential problem.

The next option, would be to just wire the hydraulic motor on the dump trailer and trailer battery together, and then directly to the high current wiring on the truck. I'm not a fan of this option because it means that I need to have the relay closed basically the whole time I'm using the trailer and I don't like such a long run of wire that could get damaged to be energized while I'm driving around.

Any other ideas or methods?

In case anyone is wondering, the truck is a 2014 Ram 5500 6.7. The dump trailer has electric brakes with a breakaway cable. Not that the trailer breaks work at the moment... but they are the reason why I can't (shouldn't) delete the battery on the trailer.

I'm looking forward to these projects and I hope you guys can help make them awesome!

  • Welcome to Motor Vehicle Maintenance & Repair! Commented Dec 22, 2023 at 12:50


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