Boat wiring questions

[elcaboing]

Hi All,

Sorry in advance for the long post. I have some questions on how my boat is wired. I have a 2021 Lund Adventure Sport. Bought in new and have been enjoying it immensely. Never had any issues with it in terms of electrical. I previously had Helix units and had a really nice 2d,SI, and DI images on them. This year I did some upgrades. I swapped my 2 trolling motor batteries for Lithium ones, and also swapped the starting battery with a lithium one. Last year I had installed a fuse panel to power my 3 Helix graphs, ML1, and 5 port switch. I ran 10g marine wire from the battery to the box, then 10g from the box to each of the items. I tinned all the connections prior to crimping and just soldered the power connectors of the graphs because going from 10g to 14-16 g was tough. Again had no issues with anything.

This year along with upgrading my batteries I also upgraded my graphs. I bout 2 Solix G3 both 12". Got everything installed and was finally able to take the boat out last week to test on the water. What I notices was some interference on my 2d on both graphs. The console is connected to a Y cable that has a MSI and high speed transducer on it, the bow is connected to my Terrova with a MDI transducer built into it. Both give me interference (vertical lines) when looking at 2D. I tried fixing it by playing with the noise option on the Solix units but that did nothing.

I had never installed the choke that was sent with the ML1, so the other day I took the battery out and was going to install it as the instructions state (my charger is a 3 bank one that charges both my trolling motor batteries and my starting battery, again never had any interference issues prior). While I was looking at things I saw some strange type of connections in the back where my battery compartment is. It was hard to see as it is under the flip up chairs so I never noticed it before. Here is how the boat is wired.

There are 2 bus bars right behind the battery that I never noticed. On those blocks, connected is the auto bilge, the charging cables from the charger for the starting battery, an 8g run to the fuse panel that has the main, bilge lights etc, with a 20 amp fuse, and 2 more connections to the battery to power those blocks with a 50 amp fuse on the positive end. On the battery, I have the motor cables, the 10g run to the fuse box I installed and the 4g connectors to the bus bars.

I left things as is for now. I had installed the noise filter between my 10g run to the battery thinking that should hopefully fix my issue. I took the boat out yesterday and it fixed it somewhat but not completely. I will install that as instructed to the other end of the charging cables.

Since I have to take everything apart to do so, I was wondering if those bus bars are really needed back there? Should everything not go directly to the battery, especially the connections to the charger? Any help would be greatly appreciated.

Steve

[TN Crappie]

I would inspect those bus bars for any corrosion or loose connections.

ETA:
When you were running the ducer cords/wires, did you keep them away from the power supply wires as best as possible? Separation is a good thing at times for these two items.

[elcaboing]

Upon further testing it seems that the interference is coming from the trolling motor. When off it's clear as day, when on, I get the spikes. I will move the noise filter to where the leads for the charger are and hope that fixes the issues. I think I will also direct connect the charging cables to the battery as to me is strange that when I plug the charger in, it will power the bus bars then will go and charge the battery.

[elcaboing]

Ok, noise filter moved to the charging ends and directly connected to the battery. Noise is still there when trolling motor is deployed. I measure 13.7 volts on the battery terminals, and 13.6 volts on the fuse box when I flip the switch to power it on. At the start of this install, I did a fast connection to the power chord for both solix units. I tinned the 10g run and the power cable to each other then used heat shrink to cover it. Originally, I was getting low voltage alarms on both units. They were coming up with 10.5V on them. Last weekend I made better connectors, and just installed the power cable to the console solix direct to the fuse box. Now when powered up I am getting 12V-12.2V out of both units. I measured the voltage coming out of the connector of both units and it measures 13.6V at bow and console. I read somewhere that the Humminbird units don't really display the correct voltage on the screen, but I am confident that the new connections are much better. I haven't had a chance to test and see if it was a low voltage issue as to why I was getting the noise, but if I head out and still have that issue, is there anything else that I can try. The power supply wires, and the transducer wires are not close to each other, so I don't think it is that.

[5keepers2]

Do you have a transducer mounted to the trolling motor ( usually underneath ). If so this could be the source of interference. It was for me. I took a computer mouse pad and cut a strip to fit underneath the transducer, correcting my problem. Yours may be something else, but what worked for me and is an easy try! I have forgotten where you now have choke. I put my choke on the power cable feeding the depth finder/sonar unit just before the unit. Within 6 inches maybe of the unit itself!

[justinp61]

If your trolling motor has brushes you may never eliminate the interference, I never could anyway.

[elcaboing]

Yeah, I guess if push comes to shove I can add quick disconnects on the charging end that connects to my house battery and only connect them when I am home charging. I am heading out today and will see if the last bit of connections I did fixed anything.

[elcaboing]

Looks like the next test will be quick connects to the starting battery from the charger.

[elcaboing]

So, the quick connect did not solve the issue. Did more testing yesterday on the water and found out that if I disable the ping from my trolling motor transducer I get no more noise. That is why even if I shut off the trolling motor I would still have the problem. Only when it was stowed it would go away. So got home, took of he head and low and behold there was no 3 amp fuse in there. I mean not blown but actually none in there. I think a few years back, I had taken the cover off to look for it, found it, brought it with me to get extras so I have them in the boat, and forgot to install it again. Haven't had a chance to test it, but I am fairly confident this will finally fix my issue. Call it user error or old age :)

[jjue1979]

So, the quick connect did not solve the issue. Did more testing yesterday on the water and found out that if I disable the ping from my trolling motor transducer I get no more noise. That is why even if I shut off the trolling motor I would still have the problem. Only when it was stowed it would go away. So got home, took of he head and low and behold there was no 3 amp fuse in there. I mean not blown but actually none in there. I think a few years back, I had taken the cover off to look for it, found it, brought it with me to get extras so I have them in the boat, and forgot to install it again. Haven't had a chance to test it, but I am fairly confident this will finally fix my issue. Call it user error or old age :)

The fuse for grounding is generally the issue for most people's interference problems when running the trolling motor, and when it blows, it is a sign that the motor needs servicing. I blew my first fuse on an old Terrova around the same time it started making some weird noises and having some spinning issues, and this is also when the interference started. Once I got the motor reworked and replaced the fuse, the interference stopped.