Blowing fuse when backing up boat trailer.

2016 TRD
First problem was with the truck side of 7 pin connector. Center pin wire had no power. So I spliced into the reverse lamps wiring. Seemed to work fine for a while. But now I blow a fuse every time I back my boat trailer up. (surge brakes, so using back up lamp circuit to energize reversing solenoid on trailer). I also now notice that when checking my truck's 7 pin connector that the center pin has continuity with truck ground (dead short ?). When this 10 amp fuse (driver side cabin fuse box) blows, it kills my backup camera, back up lights, and throws a loss of traction control alarm.
I'm guessing that I first need to trace back my original center pin wiring to see why it has no power. Is this a separate circuit or shared with the truck's back up lamps???

Any help would be appreciated.

Thanks.

 

I’d start looking in the underhood fuse box. It’s quite likely that there in an open socket with no fuse installed for trailer reverse circuit.

 

The center pin is your reverse, backup lights, connection so it will not have power unless you are in reverse with the vehicle on.

 

I can't remember if it is this truck or the silverado I owned previously, but I had to install a fuse in the fuse box under the hood to get power to the 7-pin. Truck came from the factory that way as a "standard" option

 

Thanks for the replies.