Hi, the motor and motor gauges are working but all other electronics have no power (radio, depth, lights, etc). I have a 2 battery system which has a switch (1, 2, Both). Both batteries 100% charge. I checked the two fuses at the battery both are good. I see nothing loose behind the key start on the console. Why would I go about finding the ground(s) on this boat? Any help much appreciated. Thanks.