Try cleaning the points by scrubbing them with a piece of index card, or a clean business card (NOT a file or sandpaper!) The points behind the ARM and FLD terminals are pure silver, and they can be scratched easily. They have a slight wiping action as they operate to be somewhat self cleaning, and even tiny scratches will make them stick. If you test the circuit between the FLD terminal and the regulator base with an ohmmeter with all the wires disconnected, there should be almost zero resistance. Opening either one of the spring-closed points with the ohmmeter connected will result in a reading of 5-10 ohms. The point sets behind the FLD and ARM terminals are connected in series, so opening either one will reduce the generator output to almost zero. Those points vibrate several times a second in normal operation to control current and voltage. Dirty or corroded points on either set of contacts will drop the generator output to zero. The third contact set behind the BAT terminal is a cutout relay that disconnects the generator from the battery when the engine stops
EDIT: looks like you solved the problem while I was typing! Good show!
Jerry
