Ecm B fuse blowing

On my drive to work the engine cut out.no restart. Notice no check engine light. Check fuses and Ecm B fuse burnt.had a pack of 6 10 amp fuses.the rest of my drive to work it blew 10 more fuses. Last 2 was 20 and 25 amp as I was 2 min from work. I know that's a big no no.I made a remote fuse holder for glass tube fuses and it only blew the fuse once on my drive home.that happened when I hit the gas hard.recently I changed the wire harness for fuel pump relay with a used one and the used relay.also replaced oil switch and harness as they had turned green.the green corroded wires in the pump relay had left me stranded witch is why I replaced a few obvious things.drove a few weeks with out issue then suddenly this.it has frame mounted pump.the Ecm B as far as I can tell feeds the Ecm power and pump relay and also power threw oil switch. Can a bad relay or bad ground for fuel pump or anything to do with chip blow fuses.thanks

If you're blowing fuses that quickly, especially when uprating them (which you correctly state is definitely a no-no), then you have a short to ground somewhere in that circuit that's causing 12V to go straight to the ground without going through anything else. Since you say you changed the wiring for components that are clearly on that circuit, I would start with the wires you changed. Inspect for chafing, broken insulation, or any bare metal coming into contact with them.

Best of luck in your search.