I really like your YouTube channel, your info has helped me a lot. My boat is a mess and I'm rewiring as well as everything else but my question is fusing. I bought a blue sea fuse block rated to 30 amps as well as a switch panel with 10 amp fuses all on the switches. Do I select fuse amperage according to wire size at the block? Also if I have my main engine running and start my kicker motor will it cause a spike in voltage or amperage since I only have (10 battery? Thank you. Darrell
When choosing a fuse size, you should consider the requirements of the appliance you are fusing. The manufacturer should specify the fuse size required. Also make sure the wiring between the fuse and the appliance can handle the maximum amperage, for instance a gauge 10 wire can only handle 30 amps of current.
When starting a second engine (i.e. your kicker) off a battery that is also running your first engine, you’ll definitely experience a voltage drop. Having your main engine running with its alternator recharging your battery should help offset the voltage drop when you start your second engine.