Battery becoming very hot
Here is the same circuit with orange arrows representing current flow.
With the engine turning 900 rpm, the alternator was suppling all of the power at 14.3 Volts or so. Therefore,
current flows from the alternator to everything that demands it.
The battery is drawing the most, 20 to 25 amps, because its low.
Points ignition and alternator field, say 4 amps. Notice this flows from the junction up through the key switch.
Lights, about 12 amps. It too flows from the main junction; headlight current goes directly to the headlight switch, there's a circuit breaker inside. Parking and Brake light current goes through the fusebox.
As the battery gets recharged, the current through the ammeter should go to zero.
Hopefully this also makes clear why we were puzzled that lights on would show increased charging.
Here is the same circuit with orange arrows representing current flow.
With the engine turning 900 rpm, the alternator was suppling all of the power at 14.3 Volts or so. Therefore,
current flows from the alternator to everything that demands it.
The battery is drawing the most, 20 to 25 amps, because its low.
Points ignition and alternator field, say 4 amps. Notice this flows from the junction up through the key switch.
Lights, about 12 amps. It too flows from the main junction; headlight current goes directly to the headlight switch, there's a circuit breaker inside. Parking and Brake light current goes through the fusebox.
As the battery gets recharged, the current through the ammeter should go to zero.
Hopefully this also makes clear why we were puzzled that lights on would show increased charging.