Welcome! We're a friendly bunch and sometimes, our advice is even helpful. *grin*
Sounds like you have a BIG project in store. My trailer is much newer and smaller than yours, so I don't know that my battery box is the same. I don't know of any fuses in there though. Were you perhaps talking about the two Circuit Breakers (CB) that are usually in there? If so, Post#10 in this thread is how mine is wired: http://www.hilotrailerforum.com/f51/...ry-wiring-116/
I think it's more clear than a photo.
Hi-Lo 1707T - Tire Minder TPMS on Tow Vehicle and Trailer, 300W Solar Battery Charger, Equal-i-zer WDH, Progressive Dynamics Converter, Fan-Tastic Fan
2014 F150 Platinum 4x4 3.5L EcoBoost SCrew