If interested in getting a service manual and full set of wiring diagrams I maybe able to help. PM if interested.
The wiring diagrams will give you the details needed to interface a push button start. The diagrams will give the connector face and wire colors.
Note, there are multiple gangs inside the ignition switch. So depending upon how you want to start sequence to work will require different wiring interfaces.
Note, there's a difference between a "push to start" vs a "push to crank" (hint "push to crank" is much easier to wire/interface).
The wiring diagrams will give you the details needed to interface a push button start. The diagrams will give the connector face and wire colors.
Note, there are multiple gangs inside the ignition switch. So depending upon how you want to start sequence to work will require different wiring interfaces.
Note, there's a difference between a "push to start" vs a "push to crank" (hint "push to crank" is much easier to wire/interface).