Garmin 63cv voltage drop then shut off…

[VolFan]

I recently installed the above into an already-existing fuse box. It replaced a Striker 4. I left the inline fuse intact. It worked great for one trip, then I had a couple intermittent shutdowns while going from one spot to the next. This past trip it was reading low voltage intermittently, then shut off and wouldn’t come back on. When I got back home, it turned on with no issues. Neither the inline fuse nor the fuse in the box was blown. No issues with any other electronics onboard. I checked and redid the electrical connections from the box. I may remove the inline fuse and go straight to the fuse box. 

Any other thoughts?

[Scott F]

Modern depth finders are very sensitive to voltage. Could be your battery is going bad or it wasn’t charged up enough. Or you’ve got a less than ideal connection in your wiring. Sometimes it’s just that the power connector on the back of the unit isn’t plugged all the way in. A weak battery can start a motor just fine but not run the depth finders. When my battery was going bad, my depth finder would shut off any time I tried to start the motor. Once the motor was running, and charging the battery, the unit would work fine.

DO NOT run the unit without a fuse!  If there is an issue with wiring, you could permanently damage your depth finders. 

[VolFan]

Thank you - I left out that the battery is 6 months old and on a full charge. It stopped working even with the main motor running. 
I also detached and reattached the power cord from the back of the cradle and the unit to the cradle. 
The power runs through a fuse box and there is an inline fuse that comes standard on the Garmin power cord. I was going to remove that one and just use the dedicated one at the fuse box. Right now it has two fuses, one standard inline and one at the fuse box. I’m starting to think that the inline one is a little loose inside the housing. 

[VolFan]

I’m an idiot. It’s the battery. I put it on the charger and it was at 60% after sitting for a day. Took the charger off and watched the voltage drop by .1 v every couple seconds… At least I know what it is.