when did they go to electronic ignition?

There was actually a FEW isolated field units BEFORE '70........don't remember the details.........but I DO remember that the original VR had THREE terminals...which is why the connector is shaped the way it is.

HERE IT IS NOW.........from the MyMopar files, the factory "Master Tech Service Conference"

MyMopar - Mopar Forums & Information - Browser MTSC by Topic - Electrical & Ignition System

NOTICE that what many call "dual field" the proper name is ISOLATED FIELD, and notice that in this tech writeup, the INSULATED FIELD is DIFFERENT and uses the oddball 3 terminal regulator, which was abandoned

http://www.mymopar.com/downloads/mtsc/269.pdf

"the movie version"


So here, from the movie, are the 3 alternator types as of 1970

Below, the familiar 69/ earlier "single field" terminal with one terminal grounded



Below the familiar "isolated field" -------incorrectly called "dual field" that we all know so well



And last, the oddball. This was used in "some models" of the big boats in 69, has an INSULATED field but is connected differently, AND USES the oddball 3 terminal regulator



And here is the oddball 3 terminal VR used with the oddball "insulated field" alternator