I have a boat trailer with disc brakes, it has a 5 pin connector that when in reverse it will open a solenoid that will not enable the brakes. Problem is, i do not have power to the 5 pin at the truck. Is there something that I need to add enable power to this pin? Truck in an '06 d/a 2500.

Thanks.

I had to do nothing to the truck to have power for my boat trailer like yours. There probably is a fuse somewhere.

There is a trailer B/U fuse, but mine is still good.

The center terminal in the 7 way is the backup lights, but I'm guessing you already knew that.
The only other thing I can think of is the pins on the back side of the plug sometimes get bent out when they are plugged in at the factory. I even had one in the shop awhile back that the fifth wheel plug over the spare tire had a pin bent out.