How to Wire an Electric Winch to a Trailer or Vehicle Battery with a 1999 Dodge Ram 2500

Updated 12/10/2012 | Published 12/08/2012

Question:

How can I tie a charging circuit to charge my rv battery and not feed back and kill the truck battery. There is a fuse in power control box on the LH fender of the truck that says trailer that is 40amp but I dont know if it feed back to the rear of the truck or not . The truck didnt not come with a tow package. So I dont understand why it has that fuse. Would it be a wire running back to the rear of the truck and what color would it be and will it be hot all the time or just when the sw is on. Thanks for any help

asked by: Jim

Expert Reply:

First, the wiring normally used to provide 12 volt power (most likely would flow through that fuse you have found) is not large enough to provide an up charge to a trailer mounted battery. Also, the alternators on most vehicles do not provide enough current to push a charging voltage back to a trailer mounted battery.

What it can do is provide a maintenance charge. This means that it will only keep the present charge level of the battery but will not add any more.

There are a few ways that you can power a winch. I have included a link to an FAQ article for you that covers the various methods. By wiring your winch using the best method that works for you, there will not be any backfeeding problems.

expert reply by: Michael H