I was getting to the point of suggesting that you get the manual. I wasn’t sure how receptive you would be to the $125 price. Here is the link for the download
FT 555 repair manual
A tractor with multiple thousands of dollars invested in it is of no value if it doesn’t work. So in that light $125 should be well worth it.
So to be clear the wires were burnt..?
A. It would not start or operate and you tore it apart and found the burnt wires.
B. You were testing, jumping around wires, or crossing wires and this was the result?
Either way the burnt wires could maybe be replaced with wires added on outside of the loom but you have to know what connections they go between, that is where the manual comes in. One problem with that approach is if the wire that was hot inside the wire harness melted through insulation of other circuits and is shorting them they can be negativity affected by that.