Lost all power underway except for the outboard

[Willpow]

I was out for July 4th everything was smooth on the chesapeake, water too. Next thing i know the gauges are out & trim tabs are un responsive. However the old Mariner 2-stroke kept running. I head home and then as soon as i pull back into the creek the power comes back to gauges and outboard.

Where should i start the troubleshooting?

[RickK]

With my multimeter or test light in hand, I would start at the 30amp circuit breaker and work forward.