Trailer brake help needed!!

[3 Squids]

I should of noted this is not a boat trailer. It's my enclosed 14' work trailer. Like I said it's brand new. And the magnets seem fine. Like I said if I just use jumpers from a battery they'll lock the wheels right up (I jacked one side up). It definitely seems on the truck side. Just so confusing that if I apply the 12v (or whatever the brake box is putting out) to the brakes nothing happens but the voltage from the brake light pin activates them. My buddy is supposed to come by this weekend with his truck with a box in it and try it out. I guess that'll really tell me if it's the truck or trailer.