Easy im sure but HELP HELP HELP

I am lost. You have no "start" wire coming thru the firewall, but the starter cranks and cranks "the way we are wired". How is that? Photos would help us help you. I would call the wires "crank" (yellow), "IGN1" or "primary ignition w/ key in "run" position (blue), and "IGN2" or "ignition while cranking" (brown). Colors are for my Mopars and probably thru 1970's. Your year might have the seat-belt interlock in those circuits.