Electrical issue pls help!!!

[Eightysixer23]

What's up guys! I just finished up my 20v swap that I got through a trade. The motor was pulled running on a mega squirt 20v system. I pulled the motor out myself and hooked up the motor exactly the way it was running previously . It came already wired so I didn't touch any of the wiring besides the plg that connects at the fire wall (engine harness plugs to body harness). The problem I'm having is that when I plug the battery I get sparks( short somewhere obviously) the 80 amp fuse in the postive side is the one that blows. What exactly do the white wire and the green wire that are hooked up to that fuse go to. I'm trying to determine where the short is at. If anyone could please help I'd appreciate it

So thicker gauge white wire is alternator charge line. Could the alternator be causing this problem...