I'm working on upgrading all of my ground connections to limit induced resistance noise and I question if new boats also have grounds from the block to the hull that need to be upgraded?
I recently ran 1/0 ground wire from the engine block to my aux stereo battery bank which also connects the ground to my main bank but I still have speaker noise while the engine runs. All stereo and amps directly terminate at one of the batteries or perko switch to limit any loops. Maybe I'm missing something?