Bought a new 2018 2500 Ram a couple weeks ago and towed the boat today for the first time. I have the 5 pin to 7 pin adapter and it worked fine with my last truck. Today with the new truck my trailer brakes were locking up every time I tried to back up. Read something on etrailer.com that said the lockout pin is the center pin on the 7 prong plug. I have no power at the center pin (this was tested without the trailer plugged in). I did read that there should be a fuse under the hood but I'm not sure which one it should be? Anyone else run into this issue? The truck has the built in trailer brakes but these don't function with the boat trailer since there are no electric brakes.