Low Voltage/Helix 15 Screen Flicker

[Eye_guy]

I’ve been having a screen flicker after extended operation (6+ hours) of my bow units. Primarily the issue is with screen flicker on my Helix 15 G4N, but my Garmin 93SV/LVS 32 also will at the same time tell me a panoptix transducer is disconnected. Once I turn off my Helix, everything is ok.

this issue starts to occur when voltage drops to ~10.5V at the bow. I installed a DC-DC converter at the bow to boost low voltage to 12V. However, the problem persists the same as prior to the installation except now at higher (12V) voltage.

I have two 100 AH lead acid batteries wired in parallel for my house load. So 200 AH should be plenty??? I’ve measured my overall amperage draw on the system to be 9.2 amps. Around 7amp of this is at the bow.

voltage drop is 0.8V from the bow to the stern. Most of which is across fuses and other protective devices. Only .3V of the drop is in my wiring based on what I can determine via my measurements.

ive tested both batteries at the auto shop as well as with a 24 hour duration load test.

once the helix is off my voltage issues go away. Normal voltage on everything. The boat cranking is fine. When I plug in my battery charger it doesn’t indicate the house batteries are depleted. Voltage will still be 12V at the battery terminals.

im running out of ideas and not sure how I can fix this. Is it some kind of device heating, interference, battery, wiring, ect issue?

any thoughts and recommendations would be appreciated.

[Wayne P.]

Inadequate wiring or connections. A VOM meter won't show you how a circuit performs under load since it doesn't put a load on the circuit.

[Eye_guy]

Wayne,

appreciate the response. That was my thinking as well so I’ve gone through with an amp meter as well with multi meter looking for something odd. I’ve checked every fuse, protective device, and connection and it all looks ok. I spent 4 hours doing this, I just want to rule everything else out before trying again. I’m using 8 gauge wire.

is there anything else it might be?

[Champ 2001]

If you are sure the batteries and the wiring are not the problem, then I most likely would either try another battery setup to completely eliminate the power source and then THOROUGHLY inspect the wiring and connections again, but under a microscope type of inspection. I recently had a similar problem and found my issue at the connection point at the unit fuse. I had to disassemble the connection to find it. A visual inspection looked OK. Good luck and please keep us updated!

[Eye_guy]

Sounds good. With this in mind, I’m going to turn on my electronics and let them run in the garage for a day until I start experiencing issues. I’ll swap in a fresh battery and see if that solves it. If not, I’ll be able to at least be trouble shooting while the issue is present.

[Champ 2001]

I wouldn't want your transducer's to ping for that kind of time. Maybe disconnect them if able?