Thread: Depth Finder flashing "low voltage"

You have low voltage at your crank battery that is hooked to your motor and that unit. One of your screens should show the actual battery voltage. It needs to be above 12 volts all the time even though most equipment will operate at slightly below that voltage.

Since it has done it since getting boat, go into settings and see where the voltage alarm is set. That happened to me and mine was set to high so every time I cranked motor finder would flash low voltage.

Probably a combination of crummy battery & small gauge wire to unit.

What size wire is best?

I just rewired mine and I used 16 gauge. It draws very little voltage but it is sensitive to voltage fluctuations, such as when starting your outboard. Like Cray said, I would check to see if you have the low battery warning set too high as well. It should be around 11.5 or you will get warning every time it drops, even if it is just a spike.

I suggest #12 gauge if you can get some, it's not a lot more than #16 and it holds the voltage up pretty well.
I actually used the existing OEM TM wiring harness in my old junket for the front 2 machines and I get a higher voltage reading on that pair than the 2 on the dash which are half the distance from the batteries! (#6 ga.)
I have like #12 feeding the dash units, I have NEVER once had the units "brown out" or drop out since I went with heavier wire and my little old 797c2 used to bark at me when I had skinny wiring.....

RAS

What year boat and what fishfinder? Boats more than about 8 years old were not wired for todays higher demanding electronics. My 98' was fine with a small finder on the console, when I moved up to 2 elite 7's, the dash unit dropped .5 volts and the bow was constantly sounding a low voltage alarm at 11.7 volts on a fresh battery. I ran a new dedicated line of 12 gauge speaker wire from the battery to the dash and then on to the bow. Console unit is usually 12.6volts now and bow is right at 12.4-12.5. Voltage drop in small wire can really be a big deal. The original factory wiring was 16 or 18 gauge and could not handle it.