[Tom Endy]

One of the advantages of an original ammeter is that they are undamped and the needle easily swings with the slightest current movement. This provides a good diagnostic tool. When starting the car a glance at the ammeter will show the needle swinging back and forth past the zero center. This is showing the points are opening and closing before the car starts, it tells you that battery power is reaching the points and the ignition primary circuit is operating properly.

Tom Endy