Not Ranked
Mike, 121 and 126 are wired throughout the harness. You can use 121 and 126 to a clutch switch. 121 also runs to the starter solenoid which is how the neutral safety is used. You would need to trace and open up the harness to separate the 2 functions you need. I would think it would be much easier to just add 2 wires for the VSS.
Don
|