skipnchar wrote:
My suggestion is to use a manual switch to turn them on when they're needed. At the same time set up your back up lights on your truck with a manual shut OFF switch so you can actually USE the lights on the trailer. Back up lights reflecting off of the front of the trailer will KILL your night vision making the trailer back up lights next to useless. You'll be surprised how much difference it makes to get rid of the trucks lights when backing.
I will add this to what skipnchar said, it would be nice if one could turn off the tail/brake lights also, as their reflection will hamper ones vision past front of trailer.