Looking for boat wiring expertise

I know just enough about wiring to get myself in trouble occasionally. That said, I’m working on finally networking my graphs. Added an ethernet hub and connected 3 graphs to it and powered it following HB’s instructions. That went fine and was pretty simple. Here’s my problem. After powering everything up all 3 of my graphs shut off at pretty much the exact same time after about a minute. This continues to repeat itself when I restart everything.

My current set up is as follows…
-Electronics dedicated group 31 battery which is about 2 years old (completely separate from rest of boat wiring)
-20amp breaker at battery
-10ga wire running from battery to 1 switch at dash then to a fuse block (about an 18-20 foot run)
-Helix 7 G2N at dash connected to fuse block with HB power cable
-Helix 9 G3N at dash connected to fuse block with HB power cable
-Helix 9 G4N at bow connected to fuse block with HB power cable and factory 14ga wire (10-12 foot run)
-HB ethernet hub behind dash connected fuse block HB power cable

Total max draw is just under 7amps.

Only troubleshooting I’ve done is temporarily removing the inline 20a breaker to eliminate a possible faulty breaker. Prior to last night I only had the Helix 7 and Helix 9 G3N connected to this circuit and had no issues whatsoever. I’m going to throw a tester on it tonight, but I’m suspecting voltage drop and that I probably have to swap out my 10ga to 8ga supply wire.
What say you?

Any chance you have a new mapping card in the G4 unit?
Take the mapping cards out and power up again.

I have a similar problem with a G4 unit and lakemaster card.
It goes away when I take the card out.

Interesting. I did move a map card from the dash unit to the bow which is the G4N. Is this a known issue with networking? Seems odd that would cause all 3 units to shut down.

First thing I would do is check your battery, unhook everything from it charge it check voltage, let sit a day or two and recheck voltage if below 12.5 the battery is on the way out. Many times having a load test done does not show a battery as being bad. I went thru 3 Dekas in 18 months to find a good one drove me nuts figuring it was something in the boat drawing down the battery it wasnt, just new batteries that were bad..

10 to 8 gauge is not going to do anything with a 7 amp draw, Your fine there. Need to bust out a voltmeter and start with battery voltage, note the reading. Then measure the voltage at the graphs, should be very close to the same. If not then back track from the graphs back through the switch/fuses to the battery and you should find a loose connection or bad something causing the problem. Also check grounds are direct to the battery also. FYI load test the battery, could be bad also.

I would start with trying a different battery.

Battery or your switch is first thing I’d suspect.

Like others have suggested said I would do the following probably need 2 people for an extra set of hands.
-Charge battery and then let rest over night battery voltage should be 12.6v or higher. IF not battery is bad.
While volt meter is still at the battery have someone start turning the graphs on if the battery drops below 12 volts then you have a bad battery(replace)if not go to the next circuit from the battery and perform the same test. If you see a drop at the next device that is your problem. Starting at the battery check the incoming and outgoing voltage at each device down the line, if you see a drop the device towards the battery will be the problem. Not sure what the connection on your switch is but might need to put a relay in the switch loop so that the switch closes the contacts to power the fuse box instead of the current running threw the switch.

Good Luck

Bigcrappie has it right. There is zero issue with the capacity of your current wiring setup. All the voltage drop stuff you read about is 99% BS, and only arguably has to do with signal strength/clarity and not actually powering on the units. You have something else going wrong. Definitely put a voltmeter on each connection and make sure everything is clean and tight. Don’t overlook the possibility that you have a loose Humminbird connection somewhere in the network or power cables, even where they attach to the back of the units. Since you have more than one losing power at the same time it’s a weird issue for sure, but has nothing to do with your wire size. More likely a humminbird crash issue in my mind. Get a voltmeter on the fuse block when the units are running and see what happens to that number right before they shut down. Could be battery but at two years old that would surprise me.

Sounds like it would either be a battery or fuse block issue. I’d lean battery since you mentioned that the one minute thing is pretty constant. Make sure it is taking and maintaining a charge.

After that, I’d check for loose connections (positive and negative) at the battery, switch and fuse panel. This seems less likely based on the one minute timing being constant.

The suspense was killing me so I grabbed a multi-meter at lunch and did some testing. Results as follows…

Battery – 13.2v (nearly full charge)
At dash switch – 13.16v (those that said my 10ga was fine are absolutely correct)
At fuse block – 13.15v
At each Helix power cable – 13.1
At ethernet power cable – 0.0 volts!!

Checked the ethernet connection and fuse at the block they looked fine, but no power at that positive terminal. Tried a different fuse and still no power. That circuit hadn’t been used before, but it appears it is defective. I had an open slot on another fuse block to plug the ethernet into. Voila, power to the ethernet box. Powered everything up and I was now able to access the network menu on each unit. Waypoints transferred all around. Apparently the units didn’t like being plugged into an ethernet network that wasn’t being powered. Not sure why, but maybe some of you do??

Thanks for all the input!
Joe

I just replaced a 2 and a half year old battery for a similar issue. Battery was purchased 6 months before I got the boat but my depth finder kept turning off if my rpms weren’t up. Started watching the volt gauge and the volts were dropping below 12 if I wasn’t going at least 5 mph. Read where humminbirds need at least 12 volts.

Was shocked with the battery being less than 3 years old, but I got a new battery and problem solved.