I currently have two Lowrance units set up on my Triton, an HDS 12 Gen 3 at the Console and HDS 9 Gen 2 at the bow. I recently purchased the structure scan 3D transducer and 3D Structure Scan Box. After I had the marine service center install the new transducer and box, I don't get any structure or down scan images. I figured out after talking to Lowrance tech support, that the technician didn't even have the 3D Structure Scan box powered up correctly.

I have since solved that problem of power to the box and get the green lights, but now when I have both graphs turned on at the same time, the one on the console looses voltage and resets itself. If I disconnect one of the two NEMA cables from the box both units will work, but only in 2D sonar.

Does anyone have any suggestions on this or has anyone experienced this voltage issue. If so how did you solve this. Could it be the 3D structure scan box?

Thanks in advance

Don't know who put it in and wired it up but I can tell you that the ground is the most overlooked important wire in the 12v DC system. Especially anything that pulls a high amp current. If I had a choice between 16ga for hot and 14ga for ground then the ground gets the bigger wire.
I have run double ground wires on Engine starters for high compression engines to help a stock starter along so as not to have to buy a higher KW starter.
I know this is a different kind of current draw but the principle is still the same. Once the voltage goes thru the hot wire and then thru the apparatus and hits a weak ground the voltage drop becomes exponential.
I would not use anything smaller than 16ga for any electronics wiring even though the pigtail connection wires from an apparatus may only be 18ga or 20ga. If I had some 14ga then that would be my ground wire.

Oh, and if you think battery voltage is low now, drop the Sonic Hub into the system, plug in your Ipod and turn on some ZZ Top music thru 4 speakers and a sub woofer and watch that voltage drop like a rock
In about one song the voltage is at 10.5

Ha. I love ZZ Top. Thanks for the suggestion, but both of my graphs read 11.7 and 11.3 (console and bow) when the NMEA is unplugged from the Sonar Hub. The ground (coming from the Structure Scan Box) is the stock ground from the box. Everything from the batteries to the console was factory rigged by Triton.

Have your battery checked for load. Might be time for a new and/or bigger battery.

Easy to add a parallel ground wire. Won't hurt a thing.
Many times the ground connections can be the culprit even on a new boat. Even the tiniest bit of corrosion will compromise the circuitry.

Thanks for the suggestions. Will give it a shot

For a clean electrical install we prefer to go straight to the battery. Sometimes just upgrading the head units can tax a boats internal wiring.

If it is OK when you disconnect the NMEA, it means the addition of the "box" is pulling more than the current wiring will handle. Since the NMEA is powered and suppling power to all the accessories, my guess is the NMEA is also getting it's power from the same source as the Depth finders, which is usually a junction strip. Use a 10ga wire harness (black and red)from the battery to a dedicated junction strip and connect the depthfinders and periphals to that junction strip.
John

If I turn off the autopilot feature mine will turn off and on like a voltage issue if I leave autopilot feature on it has no problem.

I would like to say a quick thank you to Lake Fork Boat Accessories. These guys met me at the ramp, and then fixed me up next day to solve my power issue with the graphs. They also set up the units to see crystal clear images. In fact it help us catch a giant fish in our tournament there Saturday. Thanks and I recommend them if you are in the area.

Please tell us what they did to fix your voltage problem.

The problem with the units was not a voltage issue. The installer left a cable connecting the units together. I'm pretty sure that was the problem. When I disconnected it on both ends the units worked properly.

The only cables that can connect both graphs are a nmea cable and the Ethernet cable. Either way you are going to lose some features or functions. Maybe the cable was bad, but most likely you need it.

With 3dss you don't need Ethernet from unit to unit. Ethernet goes from the module to each unit. You can connect up to 3 units.

So they had an Ethernet from the module to each graph and then the other Ethernet port back to the other graph? I guess that certainly could cause a screwed up situation, makes sense now.

Actually, with ANY Structure-Scan Module (not just 3D-SS) the primary Internet cable connections should be from the SS module to each sonar/graph unit. The Lowrance SS modules all have an Ethernet router built in, typically 3 port in the case of Lowrance. When you connect each unit back to the SS built-in router, you're building a network that allows any two units to communicate. So, you actually DO still have Ethernet from unit to unit, but it is no longer implemented with a cable directly between the two units.

The router executes a "discovery" protocol when the system is powered up. This is what lets it discover what devices are connected to the network so that they can assigned ports and allowed to communicate correctly. If you keep a previously installed unit-to-unit Ethernet connection in place, that makes a redundant connection which is not reconcilable by the router's discovery process. All bets are off then.

HDS Gen 2 and Gen 3 units have two-port routers built in. This is why a simple network is possible without a SS module. When a SS module is added, the old network wiring must be disconnected, then the connections rewired using the SS module as the network hub. The installer that left the pre-existing wiring in place (creating a redundant connection) didn't know what he was doing.....and shouldn't be paid like he did.

Yes. I had to remove each end of the Ethernet cable from both flush mounted units.

This is interesting. Sounds like lake fork can get your taken care of. If your close to fort Worth we can help you out. Feel free to give us a call with any questions!