Totally stumped C10 gauge not working items powered on with key off.

[Reelcrazy]

I have a 2018 300 APX with fly by wire controls, C10 gauge, troll control, and trim tabs on a Seapro 248 bay boat.

My C10 is suddenly not showing any diagnostics. I am not receiving information from the engine control or fluid level sensor.

Everything is staying on with my key off. The C10 screen remains on, and I can hear what I assume is the fuel pump in the motor running with the key off, as well as the trim tabs are still powered.

In my NMEA back bone is the C10, engine control, fluid level, power to the fuse panel. Both the fluid level and engine control are fused.

When trouble shooting I found the fuse blown the goes to the engine control. I figured this would fix my c10 once replaced but it did nothing.

Does anyone have any insight into what could possible be going on?

As far as I know with the key off my C10, trim tabs, and motor all were isolated from power. Now they all have power with the key off. My C10 displays no engine data. I have another engine control NMEA ordered but I am afraid to plug it in and damage it if that fuse previously blew and I am not getting input from the current one.

[Moonlighter]

It sounds very much like you have something wrong in the wiring, either in the engine harness or the key switch.

Did anything get changed immediately prior to this happening? If so, what?

Your terminology is also confusing - the NMEA2000 network devices you listed include a “engine control” ? What is that? If it has a fuse in its wiring, its not a network device and you had better find the reason that the fuse has blown, or have someone knowledgeable inspect the associated wiring, because that may well be the root cause of the issues. If the engines ecu is not getting power, then it will not transmit data to the network, and the C10 then cant display it. The engine wont run either.

Normally you would have network T’s with the following devices attached

- C10 gauge
- network power source, which is commonly connected to the engine harness such that the network is only powered on when the engine key is at the on position. Its also normal for there to be a fuse in the + wire of this power node
- the Suzuki engine interface cable that is then connected at the other end to the harness behind the dash via an adapter cable. Never heard of a fuse being anywhere in that connection....
- fluid level sensor that connects to the fuel tank sender unit.

So, there would normally be only one fuse on network connections.

[Reelcrazy]

The terminology I used was incorrect regarding engine control it was the engine interface cable. I am not receiving data from the interface cable or the fluid level sensor. There are two inline fuses that are associated with that who mess of wires. One of which keeps blowing. I have a new engine interface cable on order. The only changes I have made are new starting and house batteries. Installed a VHF radio, and a new garmin chartplotter. Both the chartplotter and VHF are isolated from the NMEA backbone as they go directly to the fuse panel under the console which is constant power when the master is in the on position.

With the key off my C10 powers up and remains on and I can hear buzzing under the cowl of my engine which I am assuming is the fuel pump. My trim tabs are also lit up. The motor starts and runs normally but I have no engine data once I turn the key on.

I will have to look into how that network power source works it seems to be spliced into the fuse panel which seems to be contstant power once the master is on. I don't know how it would self isolate if that was the case.

[Moonlighter]

Ive got nothing more for you.... a simple swap of one C-10 for another is straightforward, unplug one from the network, plug the other in, auto select data sources. Done.

When the network has power, the C10 will turn on. It gets its operating power from its network connection.

The fuse blowing indicates something seriously amiss in your wiring somewhere. You have changed quite a few things with batteries and installing the other displays and it sounds like something has gone badly awry.

You really need to find what is wrong and fix it. A wire somewhere may have rubbed on a bulkhead etc and be shorting... or something is connected where it shouldnt be. With the engine key off, the fuel pump or FbW servos should NOT be activated, nor should the network be active. Something is badly wrong in there somewhere.

But nobody can tell without actually being hands on. All I can suggest is to take a methodical approach and disconnect one thing at a time then test again. Repeat.

[Reelcrazy]

Thank you for your help.

[Reelcrazy]

Moonlighter I have a question regarding this installation on this boat. My power node for my back bone is connected to a fuse panel that is always hot when the master switch is thrown. How are the devices on my NMEA network supposed to power on and off via key if the power on the backbone is connected to a constant power supply? Im trying to build a picture in my mind as to what may be going on. I talked to Seapro and they advised to put the power node at the end of the backbone and put a power isolater next in line and everything should work? Is this possible? I also noticed that my backbone does not have terminators on it could these things possibly be causing all my issues?

[Moonlighter]

Ok it looks like a pretty big FAIL for whoever set that network up. If it was you, give yourself an uppercut now LOL! Actually make that 2 uppercuts, an extra one for not reading the network design instructions.

Seapro is wrong, you cant inject power into the open side of a T, unless its a special power node with an inbuilt terminating resistor.

And yes, a network will NEVER work properly if it does not have a terminating resistor at each end to close off the open end of the end T’s. DATA WILL JUST FLOW OUT THE END AND BE LOST.

This is just a basic RULE of network design, not negotiable. Networks should look like this: terminating resistor on open end of T, then TTTT however many T’s needed for devices and one for power, and a terminating resistor to close off open end of the last T. When you buy a NMEA2000 network starter kit, it includes all these components which makes it very easy to set up.

Some important, basic facts about NMEA2000 networks and power....

1. The network requires a power source connected to a T piece. But there must only be 1 power source connected to the network, more than one power source causes BIG problems. There are ways around that but they not relevant to your situation- they apply to larger complex multiple device networks.

2. Most, although not all, devices attached to the network require a separate power source to operate. Eg any device that has a separate power cord/plug on the back MUST have that cord attached to a power source in order to operate AND TO ENABLE IT TO COMMUNICATE WITH other network devices.

3. DEVICES are anything connected to the leg part (eg the vertical part of the letter T) of the T’s on a network backbone. DEVICES MUST ONLY ever be connected to the leg, NEVER TO THE top cross part of a T piece. The only thing that connects to the top cross part of a T is the top cross part of another T, or an extension cable that goes to the cross part of another T, or a terminating resistor (one at each end of the backbone is mandatory.

4. Devices can only communicate with other devices on the network when 2 things BOTH happen - the device itself is powered on, AND the network is powered on.

5. The Suzuki engine interface cable is regarded as a DEVICE. It gets its operating power from its connection to the engine. Hence, engine key turned off, no data from interface cable is sent to the network. Engine key on, data flows to the network and other devices can see the interface and it can see them. Engine doesnt actually have to be running, just the key is at the on position.

6. Some simple, low power consumption devices however get their operating power FROM the network itself. The C-10 gauge is one such device. Ergo, whenever the network power is ON, the C-10 will start up. However, in line with fact #4 the C-10 will not be able to display engine data until the engine key is also turned on, which activates the Engine Interface cable.

Now, having said that....

The most common way of setting up a Suzuki network that mainly has just the gauges attached is to pick up power + from a spare bullet connector in the engine gauge harness behind the dash, and such a wire is only activated when the key is turned on. Thus, the network is powered on and off by the engine key. And the C-10 fires up at the same time as the key is turned on. Simples.

However its not compulsory to wire the network power supply this way. But if its powered from a different source, its highly recommended that it should have a separate fused switch. Quite a few people have their networks powered that way, and simply use a spare accessory switch (fused) on their switch panel. You just need to remember to turn that switch on so that the network can work. It would be obvious in your situation because the C-10 wouldnt turn on until that switch is turned on.

It is important to be able to turn the network on and off separately from the master battery switch, if for no other reason than you dont want it to drain power when not being used eg overnight anchoring.

Forget about power isolators for now, they are for more advanced situations such as where you have things like heading sensors and GPS puck antennas on the network- and those things need to be able to continue to communicate with devices such as your GPS/sonar combo unit. And even then they are not really necessary or worth the $100+ that they cost.

So, the first step is to get your network layout sorted. Terminating resistors at each end, you will need one Male and one Female. Change the power node +wire connection to hook it up to a spare bullet connector in the gauge harness behind the dash, or at least put it on a separate switch on your switch panel. Make sure the + wire is fused. Make sure all devices are only connected to the legs of T’s.

When you have that done, check operation and see how things work.

[Reelcrazy]

First I want to thank you for such tremendous effort and time invested in a response. To clarify Seapro’s idea they wanted the power node on the end T not on the part a termination would go. between that and the rest of the back bone a power isolator T which can be had for like 20 bucks from Garmin. That still sounded fishy to me.

on to the proper fix. There are spare powered bullet connectors in the engine harness with a positive and negative that my power node can be attatched to? Thanks again.

[Reelcrazy]

Ok so I found a pigtail that was hot with key on. Removed power node from buss to that. Still no data on c10 even with new engine integration module. So I am waiting on terminators at this point. Hopefully the network is losing all data due to not having terminators. Everything else seems to be on as far as key in key off and fuse integrity. I have no idea how this functioned prior to all of this.

[Moonlighter]

Yes it does sound bad.

Also Seapro is still wrong - the recommended practice is for power to be inserted into a T as near as possible to the middle of the group of T’s in your network. Not to an end T. And none of this is going to be helped in any way, shape or form by adding a power isolating T into the mix. That is only relevant if you have TWO sources of power going into the network. Which from what you have said, you do not. That being the case, clearly they have no idea what they are talking about.

You can connect the negative wire from the power node to the neg busbar behind the dash. Doesn’t have to be to the harness.

One other thing that will stop the interface from working is the engine harness connection at the engine end. The harness must be connected to the SDS plug on the engine in order for digital data to go to the dash. So if anyone has been messing with the engine or its been in for a service and they had the laptop connected up, they will have had to unplug that connection to connect the laptop to the SDS plug during the service. If they didnt plug it back in, or plugged it into the analoge plug by mistake, then the data wont go to the network. You should check that.

[Reelcrazy]

I will check on the SDS plug but it should be in the right spot. I had engine data before and I do all my own services. Hopefully the lack of terminators is the only remaining issue.

[Reelcrazy]

I would like to thank Moonlighter for all his help in regards to my issues. I received the terminators today and installed them. I located a pigtail in the harness with key on power and isolated from the buss panel. I now have everything functioning like it should. How this system functioned at all in the first place is beyond me. Without having access to the proper channels with this sickness going around Moonlighter has been my only hope and everything seems to be fixed properly.

[Moonlighter]

Good work!

Happy I was able to help and that its working properly now.

Take care and enjoy boating as much as you can.