Bob Johnstones Studebaker Resource Website (The Startix)

There is no starter button on your Studebaker; either on the dash or under the clutch pedal. The current to the Startix is engaged as soon as the ignition key is turned to the "run" position. That current should flow to a vacuum switch on the exhaust manifold, then to the Startix. Once the engine is running the switch opens and cuts the power to the Startix. Your Shop Manual should have the schematics for that circuit.

Assuming your Startix itself is functioning properly, simply wire
a momentary switch under the dash instead of running the current
through the vacuum switch. That's what I did with my Rockne. (See Below)

Auto Electrician Manual page (PDF)