I checked and there is no fuses that came with the unit, just the positive and negative and bare ends , So do I twist the Battery Connections for both units together and then into my main wire, I ordered my wire from shut up and fish, so it�s heavy wire, But nothing was said about adding a three amp fuse between the units and the battery just the 5 Amp that he has crimped on the wire. But that sounds like a good idea.

Ditch the inline fuse holder and get something like this first so you don't have a huge mess of wires in a couple of years after you add more electronics.

https://www.bluesea.com/products/5025/ST_Blade_Fuse_Block_-_6_Circuits_with_Negative_Bus_and_Cover

I just checked the wire that shut up and fish sent me it is 14 gauge, it�s that heavy enough to run The two helix units off of, Providing a put in a fuse box or in-line fuses prior to tying into the 14 gauge ?

I'm going to answer multiple questions with this post, not just what's above. This may step on some toes as well, but I'm going to answer about what's truly good practice and correct from an engineering standpoint. That's not what is always done as it's possible to get lucky and get by with less than "right".

I would not run two large graph units combined on a single 14 gauge wire, but you might be able to. Now, I didn't bother to look up the amperage for a Helix, but 14 gauge isn't a lot of conductor, and you'll pull double the Helix amperage. Your whole purpose of going direct to the battery is to avoid voltage drop, and especially voltage "sag" when something such as the outboard starter kicks in. Drop is minimized by several factors, one of them being conductor over-sizing.. Doing the "right thing" with the wrong material (14 gauge) won't get it done as well.

ABYC standards indicate that for critical circuits (desired voltage drop = 3% or less) that 14 gauge marine grade wire can support a maximum of 10A on a 10 foot circuit. This 10' should include the power cable length on the Helix, so the 14 ga. power wires need to be shorter by the power cable length. Getting short, isn't it? So, I think you can see you might not violate the rule, but you are right against the edge in length, and close in amps.

Each power cable for a Helix should be fuse protected. This is because the conductors are typically much smaller than the power distribution wiring, and will overheat, melt, and cause trouble before the main circuit fuse opens. I'm amazed if Humminbird isn't including fuse-holders with fuses. I would never install your setup with just one fuse at the battery end; that's wrong in many ways. Companies usually include holders/fuses partly as a liability protection move. A boat burning without the fuse they provided in the installation kit is less of their fault, right? You can use individual fuse holders or a fuse block for this final power system component. Each Helix would get it's own fuse and both would be separate on the fuse block, if used.

What did I do with my Ranger? I installed a 6 fuse Blue-Sea fuse-block under the dash. The power wires from there to my battery are 10 gauge marine grade wire. ABYC standards indicate I can support a 15A load out to 20 feet on this wire and get less than 3% voltage drop. I'm closer to 10', so I get even better results in my installation. This is power distribution on steroids and will support any electronics I choose to attach to those 6 fused circuits. That 10 gauge wire is protected by a 15A fuse at the battery. It could be bumped higher with the 10 gauge wire, but 15A is sufficient, and will blow sooner if something starts cooking.

If you use a fuse-block, the fuse at the battery end should be sized to support the total load expected at the fuse block, but not to exceed the rating for the wire used. My standard use of 10 gauge and 15A will handle any bass boat setup with ease.

Thanks flipping out for your Professional instructions, I will certainly be installing a fuse block, and running 10 gauge to the battery, I knew 14 will be pushing it with two units,
Thanks again