My 37 Master is converted to 12V with a 1956 Chevy generator (12V;30Amps).
In the 1956 wiring plan a generator warning (idiot) light is shown.
Is this light necessary?
Old Bosch systems in my 30s and 50s Motorcycles need this light.
To get the Bosch generator going, a tiny field current must be supplied. This current is initially provided by the warning light. With the Ignition switch closed, current flows thru the lamp to the regulator and into the field winding. If the dash warning light is burned out or disconnected, the generator probably won't begin charging.
Maybe Delco 6V and 12V generators are better self-exciting at start-up then Bosch stuff.