Joe, what were your issues before that you had the trailer in the shop for? Burning all the way to the fuse block doesn't make any sense. Like bailey said the fuses should have burned out, long before they melted that far.That's what they're there for. What size fuses were in there? 30s? (green). If you have a separate fuse block for trailer wiring like I have nothing should be over 15amp( blue). Are you running a 4 flat system? Or the 7 pin with trailer brakes? If it is 7 pin and electric brakes I would say that the brake battery is back feeding the system possibly and melted everything. The strange part is you made it Down the road always before it happened. Do you remember if you were on the brakes, lights on, or turn signals when it happened? You could also have a wire chafed through somewhere causing a short to ground. But again that's what fuses are for. The only other thing I can think is you have soooo many lights on your trailer that the wires couldn't handle the load through them and over heated. But you would have to have alot of lights. Ha ha. But anyway, that's all I can think of for the moment. Wait! If you do have electric brakes and the system shorted out, it's all in the same harness on the truck and would have melted all the wires without blowing fuses.