rovaline
First make sure your battery is fully charged, my system use to shut down from low voltage. The only thing on my battery was the starter motor for the outboard, but the battery was too small and after an hour would drain the battery to the point it shut down, since I purchased a larger battery I have not had the problem.
If you know that the battery is good, go through all of your connections to make sure everything is tight. You may want to make a direction to the battery to rule out the in between wiring.
Hope you get it, it took me a while to determine my new battery was too small. If you have the option to watch the voltage on the screen, turn it on, it may tell you the problem is low voltage.
George