In Reply to: Re: ammeter / light posted by Tony C on October 23, 2018 at 18:00:21:
AMMETERS, especially the induction ones, have a +/- tolerance of 20%. When cranking, the gauge should show a minute amount of movement. Normal range when running and charging should be between +3 and +7 amps. Gotsta remember too many lights will exceed the amp draw. Lighting kits had two headlights and one taillight. Early 8N genny output rated at 11.5 AMPS. OHM's Law applied: sealed beam 6V lamp = 35 watts. Taillight bulb about 3 watts. Introduce a 6V worklight, 25 Watts, and recompute. One reason FORD went to a 3rd Brush generator, starting in 1940 with s/n 9N-12500, was the intent to increase the charging rate when using the headlights, and reduce it when lights not in use. It took them until mid-8N production to drop the 3rd Brush and increase generator output to 20 amps.