@wilvet. I'm not aware of the fuse you're referring to. There is a circuit breaker on each switch which you've indicated none have tripped.
Next place to check is on the positive cable near the battery there should be a circuit breaker there. Make sure its not tripped.
If all of that is ok, you most likely have a ground problem. Remove connections at battery, clean and reconnect.
Still not working, chase your main ground (tight fit, but you can see it feed in from the side of the boat from under the helm and runs across the bottom of each switch on both switch panels) Make sure they're all connected and none are damaged or accidentally been pulled off putting stuff in/out of the helm storage compartment)
let us know how you make out.