'fleet/taxi' wiring bypass diagram.

jeanart said
In the 65 amp alt configuration R6B and A1A go through a separate grommeted firewall hole, terminate at the ammeter and do not pass go or go through the infamous "big splice". The big splice gets power from the A1 wire though the bulkhead and is somewhat isolated

Yes we agree. That's what my diagram shows.
My second diagram is a speculatation on why the 6 gage wire extends from the terminal block.
What I am suggesting is that this particular wiring is a modification of some other fleet wiring that did not cut the wires. My guess is that its the remnant of another setup, but not the standard one. This is why the 6 gage wire continues to the ammeter stud; from there some of the power went to battery, maybe some to the mystery A1-12R, and most to the main junction.
I'm basing this on the presumption that a regular '72 Satelite
a) has alternator power going to the bulkhead connector, and
b) does not have any extra wires on the battery side of the ammeter.
So its just a guess.