My 55 Chevy wiring was cobbled together over the years, mostly 30 years ago, when I was young enough to know what I was doing...lol. I have virtually everything in the car running off a 10 gauge (maybe even a 12?) totally unfused wire that I jumped off the starter large BAT terminal and ran to the ignition switch and fuse panel (scavenged from an old MOPAR) for the “always hot” circuits. The “key on” circuits jump from the ignition switch also. So essentially EVERYTHING is traveling along this wire. Upon deep reflection and soul searching, I’ve decided that the younger me may have been a bit over confident in my knowledge of automotive wiring... although, you gotta give credit to that little wire for hanging tough all these years. So now I’m thinking of retiring the little wire for an upgrade. ...and finally..the question: Assuming I pick directly off the battery and use a maxi fuse, what size fuse? I actually found a schematic I put together back in the day, thinking some day it would come in handy. It’ll answer your questions about what circuits are in the car.