What to do under the dash besides this?

moparmat2000 said

when adding all these circuits and 100 amp alternators which seems to be what a lot of folks are doing now, you would probably want to run the alternators output straight to the battery and just run a volt gage.

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Matt. When adding circuits with significant load, a distribution point close to the battery and alternator would reduce or eliminate firewall connections carrying the combined high current that they all need. How to to do it best depends on the what the new have to do and whether they will draw on the battery or the alternator.
A nice way to avoid sending power from the alternator through a fusible link for running equipment is to have two circuits from the alternator output. One for charging that has a fusible link, the other to a fuse-relay-circuit-breaker box. If the battery has its own feed that box with a fusible link, then everything is pretty much covered.