I recently purchased a jet boat and the existing alternator was bad so I changed it, the existing wiring was 10 gauge from the alternator to the battery with a 30 amp in-line fuse, once I change the alternator I had to add a diode to prevent run-on, once I did this it started to charge the battery but blew the 30 amp fuse, Right now I have it directly wired from the alternator to the battery and it’s charging with no run on, my question is do I need to put an in-line fuse before the battery and if so what size, or do I even need one?
