Blows Main Fuse at 1/4 Throttle???

you dont have current anywhere near 30a going through regulator, 30a is a lot of current, even if regulator f@@@@d it would only increase volts to battery not amps. that kinda current is a dead short, is cable snagging somwhere ie on body? sleep on it then go double check, hint, big wires = big current,you gotta be looking at cables 4mm upwards, i know on my barracuda there was a thick cable from alternator going thru bulkhead into ammeter in dash, man that cable was toasted! i replaced it, ran another thicker cable in parallel direct to battery solonoid.<keeping ammeter> wiring/electrix just need to be broken down into circiuts and not letting a bunch of wires confuse us, i bet you could single out a hot chick in a room full of uglys? just single out that wire in same way, good luck,let us know