UPDATE: 4/11/20 Final analysis and solution below. _____ Original post:   I have a '51 Dodge Coronet (D-42) with gyromatic that's been converted by the previous owner to 12v with one-wire alternator. If you have a link to a previous post about the issue/questions below, please share.   Issue: No spark from 12v ignition coil (with required external resistor in place and properly installed).   What happened? When I got this car, there were some wir