Ok folks, I need some help. The z519 I got this year is ready to get the dual graphs on the bow wired back to the battery compartment where the dedicated electronics battery will be once it arrives. I will be running a 126 ultra and a 106 ultra from the bow along with the GLS10. I have one 126 ultra flush mounted at the console, currently run to the cranking battery, which will be switched to the new battery when I get it so that one is already run. 

I am inexperienced and lack knowledge about wiring and can use some advice on how to do the job myself to avoid paying the shop hundreds of dollars to do it. How should I do this? Can I run the wiring for each graph through the conduit straight from the bow past the console to the battery compartment and hook each up with an inline fuse? SHOULD I do that? Should I use a bus bar or a fuse block? 

Garmin says to use 14 gauge wire for extending it the length I need to go. Do you recommend heavier wire to optimize my signsls and images?

Thanks for your help! I would like to get this done right myself but need to borrow some knowledge!

Run a 10 ga red wire to a fuse block and another  10 ga black wire to a ground buss and run your graphs from them.

There are a ton of different ways to do this.  I do not have the front compartment battery.  I have all my graphs and accessories pulling from a Ionic 125.  I ran 8ga wire to the bow and then another run to the front.  each run is hooked up to a blue sea fuse box.  From there I ran 10ga on the bow to the graphs wires.  Its probably over kill but who knows what will get expanded down the road.  I built it so I can expand if needed and fuses are simple to change.

14 gauge is probably fine if that's what Garmin recommends.  You could go to 12 if you wanted, but I wouldn't suspect you'd gain anything, other than piece of mind.  I wouldn't go beyond that, as thicker wire is not only more expensive, but takes up more space.  Sonars aren't like trolling motors.  They'd don't pull high amounts of current for long spans of time.  So just barely thick enough is plenty thick.  Anything beyond that doesn't improve performance.  Though, it doesn't hurt anything ether, other than your wallet and maybe some space, if you your wires get king of cramped. 

 

You could do inline fuses or you could use a bus bar.  They both do the same thing.  The advantage of a bus bar is it keeps your fuses all in the same place.  So they're easier to access and a little more organized.  But functionally speaking, they're identical.   And really, how often do you need to access them?  How many times have you blown a fuse? 

Garmin is recommending 18 gauge for one unit.  Some people run a dedicated wire from the battery to each unit.  I would never consider doing that but that's your choice.  If you run a single wire from the battery to the front to a bus bar then you will need bigger wire.  Smaller/longer wire has more resistance which means more voltage drop in the wire because the voltage drop is a product of the resistance and the amount of current going through the wire.   Does less voltage mean worse performance?  That can be debated.  Many people are running 16 volt batteries because they feel the higher voltage gives you better performance.  Garmin says their units require a minimum of 9 volts.  I don’t know if you would see a difference between 10 volts and 12 volts.  I would rather spend a little more on bigger wire than risk it.
 

We can do the math to estimate how much voltage drop you will see with different wire gauges.

 

According to the Garmin website the 125 will pull a maximum of 3.3 amp and the 106 will pull a maximum of 3 amps.  So 6.3 amps total.  I doubt they pull the maximum all the time but let's use 6.3 to be safe.  I'm assuming you will need 50 feet of wire from the battery to the front and back  (25 feet each way).  I'm assuming you're using a lithium battery with 12.8 volts.  Using one of the voltage drop calculators available online this is what I got.

 

14 gauge - 2.5 volt drop -  10.3 volts to the units

12 gauge - 1 volt drop - 11.8 volts to the units

10 gauge - 0.6 volt drop -  12.2 volts to the units

8 gauge  -  0.4 volt drop - 12.4 volts to the units.

 

Personally,  I would run a single 8 gauge wire to a bus bar in the front.  There's not a big enough difference between 10 gauge and 8 gauge to matter but I like to add a little extra capacity for future expansion.  You might want to add one of those 20 inch FFS screens in the future. 

 

Here's a link to the calculator I used if you want to change any of the inputs.

 

https://www.inchcalculator.com/voltage-drop-calculator/

Thanks for the input fellas. That helps a lot! I have a pretty good idea what I’ll do with it now. Thanks again!