My understanding is that the wire from the S terminal to the coil is to boost voltage at cranking. I think I recall testing this wire when I installed my ignitor and MSD ignition. It was only hot when the ignition switch was in the "start" position.
Is this incorrect?
I'm a hobbyist. Not a professional. Don't be hatin'!
Correct except it's the R on the solenoid. If you hooked it to the S then you would have the problems John(Nash) spoke of. You would 'power on' the starter with the power supply to the distributor when you turn on the ignition.