Dear Sir,
Please read carefully. If you have converted to 12V and have a 10si Delco alternator,
1. You DO NOT use a regulator.
2. You DO need a ballast resistor.
3. Wiring for alternator is as follows.
Wire from alternator terminal 1 to ignition switch ACC terminal. (or a separate ignition switch terminal than the battery connection)
Wire from alternator terminal 2 to big stud on back of alternator
Big wire from battery or starter to big stud.
Ignition wiring using 12V coil:
wire from ignition switch "ON" terminal to one side of ballast resistor.
Other side of ballast resistor goes to positive terminal on coil. Also a wire from foot start "side terminal" to coil positive terminal.
Assuming you still have original foot start and ON/Off ignition switch
Important: You say alternator has no sign of life. Hook it up as I describe, then put a volt meter/multimeter on alternator. Set to DC volts. Red lead to big stud, black lead to chassis ground, should read +/- 14V at medium high idle. Let us know what it does read.