Wire Alt to batt

I would AT LEAST pull your bulkhead connector apart and inspect and repair. I often refer to the MAD article NOT because of the bypass specifics, but at least that it documents how and why these get damaged, and some illustrations showing the bulkhead connector

AND the simplified diagram on their page shows a VERY good overview of why, what, etc

One of the more rare problems is the "welded splice" In my lifetime, and at least one, maybe two on this board, "I" have either discovered or been made aware of about a dozen cases that I know of where the welded splice came apart. Be aware of that

The very first bad welded splice I troubleshot and fixed was in about 1970--1972, in a friend's 68 RR. His ammeter was going nuts. I had the entire dash/ cluster/ harness torn apart and strung out in his apartment parking lot, LOL. He thought I was nuts, I was wondering, myself.