2004 Mercrusier 5.0 (305ci). When I turn off the engine after running at cruise speed for 30 minutes I lose power to the dashboard and the engine will not restart. I still have still have power to things like the horn and blower. There is no power to key ignition, when turned to "on" there is no beep, and no response on any gauges. And then turning the key to "start" there is no engine cranking. After cooling off, perhaps an hour or more, the key "on" returns to normal, all gauges function properly, and the engine starts without issue. The engine runs very smoothly, idles well, but after running again and turning off again there is no power to restart.