I assume this is the same problem as in your other 3 posts?
You will prob get a better answer if you state everything that led up to the event of it not starting...... ie..... you installed the elec fan.
Somethings got a direct short
I'd start at the starter crank wire or "S" terminal, netural safety switch if it isn't them, then i'd unhook your toggle, relay, fan setup and see if that allows you to crank it. If that doesn't work, try unhooking your dizzy pwr and see if it'll crank etc... when you get it to crank, hook the dizzy pwr back up etc......