I have a Champion boat and a Lowrance GPS at the console. It is wired to the main power switch and when I crank the motor the GPS shuts down. This does not happen all the time just sometimes.

Any clues as to why this happens?

Thanks

May wire it directly to the battery. My radio does the same thing and I am thinking thats the problem

That problem is normally when the battery is not fully giving 12.7 volts. Check your battery.

that is the power drop from the amperage needed to turn the engine over, takes alot of power and if the battery is less than 12 volts will cause newer electronics to shut down (safety feature on most of em). be sure the battery is holding a full charge, how old is it? I run both of my 717's off a small deep cycle battery, only the finders hooked to it, yeah a little extra weight but worth having good power everywhere when needed. also can turn the motor with it if need be. 82 champion 18'8"

Thanks for the replies, I think my cranking battery is going South.