Do not rely on field disconnects in battery
selector switches to prevent burning out the alternator
diodes when your system is wired such that the alternator can be disconnected from all batteries.
Do not place any fuse or disconnect switch between an alternator and at least one battery
. That one battery must be the one that the regulator
is voltage sensing. If one MUST follow the letter of ABYC wiring
recommendations by fusing the wire between the alternator and battery AT THE BATTERY END of the wire ONLY then wire in a diode in parallel with the fuse with the cathode connected to the battery end of the fuse. The diode must be rated to carry the maximum alternator current
. The wire also must be rated to carry the maximum alternator current
ALL alternators are by their nature current limited into a short circuit and, therefore, no fuse is needed at the alternator end of the wire. Should the wire be shorted at the alternator end the fuse will blow and if the short is removed then the alternator will still "see" the battery through the diode and not blow its own diodes due to the fuse being open.
I agree that you should learn to "program" the Balmar
regulator yourself and verify that it is wired correctly. If you have the optional alternator temperature sensor and follow the aforementioned recommendations you will have a fairly robust system, assuming that you do a good wiring installation
with strain-reliefs etc.
If you find an 80A Hitachi it shoud be a drop-in replacement and most of those are capable of generating over 90A, the safe reliable limit for the belt on your engine