[When using high out put alternators the alternator should be CORRECTLY wire sized and CORRECTLY wired direct to a distribution block with protection on that circuit. The distribution block would be linked direct to the battery. All circuits then would be CORRECTLY fused with relays as needed out of the distribution block.
Some C-bodies of the seventies had such a distribution block in the form of an insulated stud that mounted on the inner fender panel near the battery...when junk yard hunting in the old days I used to snatch these up for use on my rods. Hi-amp loads like power windows/seats and tailgates drew their power from this stud.
Nowadays I use this:
https://www.summitracing.com/parts/rra-fs46540
