Humminbird troubleshooting

I bought a new to me boat today, and it came with two Helix 12 G2N units. They both worked fine during the test run, but when I put the boat back in the water an hour or so later the SI on the dash unit wouldn’t work, then it cut off. It had ran for about ran for about 10 minutes on the gps/depth finder display before cutting off, and all was fine. The unit would power up and then cut back off after that.

I was able to put it in diagnostic mode, and the unit was reading 0.0 volts, but the display was on so obviously that wasn’t right.

I dove into the birds nest of wires under the back deck while on the water and found an approximate 24 gauge two pair cable with the hot wire broken in half. I don’t know if it was broken before I started looking around or not. I stripped the two wires back with my pocket knife and twisted them together the best I could, but it didn’t make any difference. Obviously I need to address the cut wire, but does anybody else have any other ideas?

Does the unit have an internal battery? From what I understand the unit has had zero power to it (battery disconnect switch) for a couple of weeks.

HB units do not have an internal battery ...

Sounds like the power circuit (to the unit) needs investigation (too small of wire or bad connections) —- and/or battery health needs investigation ..

Rickie

I have a Bird SI G2N and its finicky about applied voltage. Often times it will see a battery or wiring issue long before i know its there. I have alleviated all of my issues by using oversized conductors with a 600v ul rated insulation and quality terminations. Little more cost but no more bs wiring issues. You may also check battery with a load tester for the possibility of a bad cell. I'll bet the unit itself is just fine. Best of luck

One other thing to try.... you said it came with 2 helix 12s ?swap the heads and that should give you a good idea where your problem lays.

I will switch the heads, and greatly improve the quality of wiring. I’m just confused why the unit said 0.0 volts while the display was on. That seems impossible.

Could no si image being displayed be due to a voltage issue?

First thing to do is get rid of that 24 gauge wire. It is way too small. ABYC recommends 16 gauge wire as the smallest wire used on a boat. i.e. lights. Of course other things may require larger wire. And I use twisted pair for everything. Its easy to make and is great for combatting possible interference.

Make sure it's not run to the fuse panel too. It needs to be wired straight to the battery. I used 14 gauge wire to power my units.

My helix 10 was wired with 16 ga. and I had low voltage issues. After recommendation here I upgrade mine to 12 gauge a couple years ago and problem solved for me.

We had the same problem with our Solix 10'S. We went to 10 gauge wiring with a dedicated circuit and an inline fuse.

Problem solved.

There is another thing that has been mentioned here but cannot be over looked. At every connection point there is current flow drop potential. Every connection from source to whatever you are supplying power to should be better than or at least equal to the wire supplying said power. A weak connection is akin to turning on your garden hose then standing on it. There is going to be a flow drop. It is the same thing with say a drill in your shop. You plug it into a skimpy drop cord, that cord cannot supply enough flow to the drill. You run the drill long enough it will fail. Last thing I have on this is using a quality diabolic anti corrosion grease. Good luck :cheers2

Sorry folks, grease is not diabolic LOL Dielectric grease would work much better. My old brain may have a bad connection.

I solder and heat shrink every connection on a boat or boat trailer

Very good possibility that you have a bad battery as you stated worked great when first tried out the boat then after you purchased the boat did not. Charge battery pull all connections let sit for a day or two and if voltage is below 12.5 the battery is on it`s way out. A load test will not always show a bad battery.