Sonar Power / Accessory Wires

Hello,

Looking to add another Humminbird to my WX1910…because, toys.

The fuse panel lists Acc 1, Acc 2, Acc 3, Radio, Radio, Acc 6, Acc 7, and Acc 8.
Under the console I can only find the wires for Acc 1, Acc 2, and Acc 3 (all in use).
Are Acc 6, 7, and 8 all up under the bow point, or should there be any more under the console?

If there aren’t any more free lines under the console, what’s the best thing for me to tap into for power? Can I easily pull an unused line back from the bow? Other options?

Thanks!

With the battery disconnected, if you remove the fuse panel so you can see the back where the wires are connected, are there actually wires connected to all the fuse terminals?

In most boats, they leave empty slots in the fuse panel. Even though there may be fuses slotted into these circuits on the front side, there are no wires run to the back side of the fuse block.

I would pick one like Accessory 7 or whatever and run your own wire to the bow. Find out he amp draw of the device and calculate wire size based on the feet of run so that the wire has the correct capacity. Many depth finders are very sensitive to voltage drops and you’ll have no end to the problems if you undersize the wire. If in doubt, go to the next size up.

Grouse

Hmmm…pulled the fuse panel and there’s a whole bunch of jumper cables connecting all the fuses in series. Do those panels use a single ground? Ie., individual hot wires in, but a single ground out? Anyway, the wire bundles inside the gunnel make it hard to track wires to figure out where to pull one back from the bow.
What if I spliced the new power line into the wires for one of the other sonar units that are easy to get to under the console? Any issues that would potentially create?
I’m no electrician and can’t always get my head around the electrical logic of what’s okay to do and not okay to do. I’m already heading to SBC in a little over a week, so maybe this one should be added to their to-do list?

I wouldn’t splice. Could create issues if the wire isn’t sized properly for running two units.

Typically, you should have a negative terminal block at the fuse panel. It is possible that the fuse panel will have a single large ground heading back to the battery.

If your plan is to mount a graph at the bow, take a look behind the bow panel. My skeeter had wires for a bow unit tucked behind that panel that were already wired to the fuse panel. Although, using those wires gave interference from other accessories in the boat. Ended up running new wires all the way to the battery using a switch and fuse at the bow.

Humminbird recommends you run your power directly to the battery, not through the fuse block. This is because they are very sensitive to voltage drops. When I originally installed mine, I had problems with the unit cutting out when I turned on the aerator, lights, etc. Called Humminbird and that was their suggested fix. Of course, if you do this, remember to install an inline fuse.

All sonar/gps units, not just hummingbirds should be hard wired directly to the battery. Probably the biggest mistake people make when rigging a boat is wiring sonar/gps units through a fuse block. You will have voltage issues down the road, especially after the battery gets older

Benny wrote:

Humminbird recommends you run your power directly to the battery, not through the fuse block. This is because they are very sensitive to voltage drops. When I originally installed mine, I had problems with the unit cutting out when I turned on the aerator, lights, etc. Called Humminbird and that was their suggested fix. Of course, if you do this, remember to install an inline fuse.

The problem isn’t wiring to the fuse block itself IF the block is properly installed with appropriately sized input leads from the battery.

The problems almost always arise when people try to use undersized wire from the fuse block itself or they try to tap into existing circuits that contain undersized wire for the load or have other active loads on the circuit. The resistance of the fuse block and the connections has to be taken into account when sizing wire.

Almost all freshwater boats contain hopelessly undersized wire that may meet the bare minimum spec (if a spec exists), but that is all. Basically, it’s cheap, cheap, cheap. I’ve replaced factory bilge and livewell pumps that were installed using 18 gauge wire which, while it will make the pump operate, is grossly undersized for achieving proper rated performance.

So yes, wiring to the battery is the “win ugly” solution, but as you say the problem is that many will fail to add the required inline fuse, which can make bad things happen down the road.

Grouse

Michael C. Winther wrote:

February 21, 2017 at 9:27 pm#1675918
Hmmm…pulled the fuse panel and there’s a whole bunch of jumper cables connecting all the fuses in series. Do those panels use a single ground? Ie., individual hot wires in, but a single ground out? Anyway, the wire bundles inside the gunnel make it hard to track wires to figure out where to pull one back from the bow.

Mmmmm. I think I know the arrangement you’re talking about. What brand is this boat?

Yes, there will be a common ground. In a proper installation, there should be a terminal block to make easy connections to ground possible.

But so many boats now are built cheap and nasty, so there more likely is a hairball of crimp connections. Yuck.

If you have the right tools, tracing wires to the bow is fairly easy, but I often prefer to just run my own wire so that I know it’s good wire, properly sized, and with no cheap and nasty connections, not run through unprotected holes in bulkheads, etc.

Grouse

I think having SBC take a look and add is a great idea if you’re not familiar with the wiring.

I have an MX and I had all Acc wires under the dash and at the bow used up with electronics and accessories. I also have a house battery for running accessories only. I had problems with my graphs shutting off with a power changes with my livewell pump kicking on and off. If you’re not running a bunch of accessories (graphs and the like), you may be just fine with the factory’s Acc wire system.

To solve this, well still working to this point with no graph shutoffs, I ran a dedicated fuse block under the dash. Like Grouse suggests, I ran heavy 8 ga. wire to the panel. Everything I researched stated this should be fine. Hopefully I don’t have problems as others are suggesting may arise after my battery ages.

Before this new setup and in previous boats, I always used to run my power for graphs direct to the battery (fused of course). This is a great way as well as others have suggested.

On my 1825 MX all the accessory wires were behind an access port under the console. except the one that was behind the bow panel.
I have 4 graphs, NMEA 2000 and a HB 5-port hub wired to the factory acc wires powered from a group 31 battery that is also the starting battery.
I don’t have any problems with interference or graphs shutting down when I start the motor.

thanks for all of the thoughts and input, guys!

my current boat is a Skeeter WX1910. if there was another easy-to-find wire i’d just plug in and probably be happy. but i guess they think 3 open accessory leads is enough? silly boat builders.

i’ve never had the power issues using a fuse block so my bias it that it’s fine. but as i add more draw, the odds increase something will show up if the wiring is “just enough” for a lighter load. so based on this conversation i’m now leaning towards shifting the sonars to a house battery with big wire to a shut-off switch, and in-line fuses between there and the units. just have to solve the on-board charger issue for the 5th battery and probably do some more prop testing as i add more weight to the back of the boat.

really, really, rigging this boat to the nines…winter’s are hard on my pocketbook!

Grouse,
could you explain “win ugly”. Having dedicated wires directly to the battery with a fuse is neat and clean. All the wire runs are there, from the dash to the starting battery. No need to buy extra fuse blocks and the added installation of it. Just another connection in the circuit that could have a problem.