Charging system troubleshooting

as an aside: thought you needed to run the replacement, "blue" electronic regulator, when staying with the single ballast and electronic ignition?
Direct Connection used to advise using an electronic voltage regulator when using the electronic ignition.
At the time, all they could offer for not rewiring and changing to 'dual field' alternators was to use their blue regulator. Supposedly the problem was the switching noise in the mechanical regulator. But now there other electronic regulators for that control the feed. So now I don't know if there actually is an advantage to ground controlling regulation over feed controlling. Could be something more subtle - an electronics person may know or be able to figure out more.