Each cars wiring issues are unique. I'm not electrically talented, its voodoo to me lol. I did the MAD amp bypass as I was having elec issues and saw the amp gauge flicker a few times(smelled some smoke too).
The bypass may or may not be a benefit to you, but one thing for sure, clean all bulkhead connections thoroughly, and check for melted burnt wires. Our 67 wiring was in good shape, but the insulation was cracking. Harness was 55 years old...I made a new harness, tedious but I enjoyed it.
Heres what I followed for the bypass.
Catalog