Forgot to answer your question, really.
The issue is just that we are waiting on a new SP switch now because of old one was completely rusted out inside but before we discovered that we were trying to hook the starter up to the wires that ran from the cab but werenít sure we were doing it right... so Iím trying to get a better understanding of what this diagram says anyway I can.
For example on the tractor... thereís a thick wire that runs to starter from back left battery suppling constant 12v. But from what I remember there are two wires that ran from the starter to the cab.. a purple and a orange one.. I followed them to a plug under the dash... and eventually traced one back to the sp switch.. but this plug I mentioned. On one side there are 4 wires running into it and on the other side only three. I just donít get it well enough yet and why thereís a wire ran that doesnít connect to anything? the diagram even shows three wires running out of this plug, one to the starter. I have an extra Iím not sure about?