Very Confused!

Reminder. Basic electric. Amps is CURRENT FLOW and Voltage is the driving push.

If the alternator is pushing 60 Amps and finds resistance at the bulkhead connector plug it will try to boost the voltage PUSH.

All the amps from the alternator go through the Bulkhead connector TWICE, once to the AMP meter on a 10 gauge wire, then through again on a 10 Gauge wire to the battery. These connectors have been known to get hot and melt the bulkhead plastic.

On many "Server Usage" vehicles like some trucks, Taxi's, Police.... They did a Bulkhead by-pass with two 10 gauge wires on a heaver connector that was a bit better weather proofed.
Happened to me, melted bulkhead connection. Good place to check for corrosion.