this should help
the wiring should be 14 gauge wire, 16 gauge will work if you have to. You can use 14 gauge wire from the solenoid or fuse to the switch, but 12 gauge is better.
You should be able to get the wiring connectors and wiring connector housing from deere.
that is where I get mine.
I have made several wiring harness over the years and I like the 14 gauge wire the best.
good luck and have fun
that is the only diagram i could find also, the wire harness i bought belongs to this diagram, yes, i broke down and bought one. it is for tractors 10000 to 24001 tractors, most of the wires are the same except my 1968 has 2 black wires and 1 red wire going into the regulator, the harness has a brown white wire and an all brown wire with a green wire inbetween. the second difference is the pink wire in my 1968 is replaced with a white wire in this harness. the white dead ends in a 3 prong harness down by the stator, there are no other wires to hook it to. another difference is the keyswitch on a 1968 is a 4 prong versus the 1969 that has a 5 prong,
S this is the diagram keyswitch D S
I B B this is my 140's starter switch
A R C
which wires go where.....? I know C battery lead from the starter solenoid, S goes to the starter, B is the accessory "D" belongs to ???