Power flows from higher voltage to lower voltage.
The Alternator supplies power around 14 Volts.
The Battery supplies power around 12.5 Volts when the alternator is not running.

When the alternator is running the battery floats closer to 14 and pretty much all the power is drawn from the alternator.

Wire R6 goes from the Alternator to the Bulkhead connector to the Main Splice.
Distribution occurs at the Main Splice.

Power distribution is hooked to the ammeter. It is wired to the ammeter from the Main Splice; the exact same way as the headlights, the fuse box and other circuits.