Fernando, I think Rodolfo is demonstrating to the rest of us that powering the solenoid and starter
of an engine with the same bank that, concurrently, is powering delicate electronics can create voltage spikes (the source of his failure)...and in that sense, his radar
is ''interfaced'' with the rest of the boat.
If a cold reboot doesn''t work, IMO his task is to locate the fuses and - hopefully - be able to replace them.
Let us know what he finds, if that''s the direction he takes. And encourage him to buy a breaker, some wire and an engine start battery.