Dodge Ram reverse lights when trailering

I'm using a 2002 Ram 1500 to tow a boat. Everytime I hook up the wiring harnesses I have funny light problems.
With truck lights off, everything's fine (turn signals, brake lights, reverse lights)
With truck lights on, turn signals seem to be slightly crossed, truck reverse lights come on when brake is applied, and brake lights don't work.

As far as I can tell, the harness is wired correctly (because of how it works with truck lights off)

I've towed the same boat with two other vehicles with no problems and have had the same problem with this truck and other trailers.



Thanks for any help.

bleedat . you probably need to hook up a good ground wire from your boat trailer to your truck.
it is not makeing a good ground on the trailer hitch. and that causes all your trouble