Sometimes I get radar echos and other times not. I'm really thinking that the issue is power related - voltage and current. Often, the unit just shuts down and I have to restart it. I replaced the ships batteries with new, and also replaced the battery charger with a new 20amp charger. How is the unit power cable supposed to be connected to ships power? Is it supposed to be wired directly to the battery with a 15a/7a fuse? Right now, I have it connected to a terminal strip that is wired to a 15a breaker.