Originally Posted by Bigshankhank
What little I've learned from restoring motorcycles and working on cars for 30 years is, manufacturers do not put more than what is needed in their electrical systems, because on a production scale adding $0.10 to the cost of a single wire gets very expensive when they build thousands of them in a month.
In other words, the original wire was probably barely sufficient for the OEM 50-amp current, in addition to being 30 years old and having decayed in that time, you should upgrade it.

I've decided to replace that wire with a 4-ga wire and a slow-blow ANL fuse. That should cover everything.

1987 Montero SWB, 2.6L, 5spd
Weber conversion
2-valve head from Engine Machine Service
"4G54 FTW!"