Engine hours flashing/blinking/jumping random numbers

[colliejo1]

After a day of unfruitful searching, I submit. I have an odd problem
The setup
2016 twin DF300AP with two C-10 gauges. Engines have approx 150 hours on them and Im the new owner of this boat. Last boat had yams so still learning what I can about these motors.
If I understand how its wired correctly, the engine interface cables run to a N2K backbone and then 2 gauges come off that same backbone. power comes into the backbone at another T so there are 5 Ts with resistor caps on each end

The problem
This has occurred the last two trips. I leave out and everything is runs great, no issues. Sometime during the day something changes.The hour meters on the gauges randomly blink between the proper hours and some random numbers about every seconds. For example: 150.4h, 00:46:00, 150.4h, 150.4, 00:46:00, 150.4h, 00:10:00... etc. the random blinking number changes in some discernible pattern. When that happens the fuel economy goes to garbage, goes from 1.8 to 1.3 for example. The engine RPMs also get a little unstable. Its only about a 200 rpm jump every 10 seconds. Its hardly even noticeable on the gauge but I can hear it.
All other engine data reads fine, the voltage is around 14.2, rpms, tilt, temp, fuel used, etc all looks normal.
The first time once it was back on the lift, I went under the helm and made sure all the N2K connections were made tight. A week later, I ran the boat it was fine. but it happened again about 6 hours later. this time snugging up the N2K connectors didn't do anything
No other alarms, codes, or check lights on
Its peculiar because it works perfectly sometimes

Questions?
Is it possible a faulty N2K Tee could result in partial data error/flashing on the hours? I could see it resulting in intermittent total data loss but not partial. I purchased a 4T solid back bone to eliminate some connection points but haven't installed yet
Should I consider re-configuring the gauges?
Is it more likely that this is an engine based issue and the gauge is just displaying that the engine is unhappy by flashing hours? Is if possible the hours flashing relate to some code?
Anything other recon I need to do when I go down the boat Thursday to help diagnose?

[Moonlighter]

Its unlikely to be a gauge problem. Dont reset the gauges yet, as I said in a recent reply to another member, if the gauges turn on and work, they are 90% of the time just fine. They simply display data sent to them via the network and if data is missing or messed up, its almost always due to a networking issue, not the gauges themselves. Its the old gigo principle - garbage in, garbage out.

And a faulty T will lose all data, not just some.

I am a little suspicious that it could be a voltage issue - because you said that it worked fine until 6 hours into the trip then went crazy - I am thinking that the voltage to the network may have dropped off due to everything else electrical drawing power down ... or, a power wire that is too small or Is corroded internally is getting hot over time, and losing conductivity. Voltage may look good but amperage may still be less than required for stable network performance.

Have a look at the power wires for the network power. Undo, clean and re tighten all connections, both + and - wires. Thee should be a fuse in the + wire, so undo the fuse holder take the fuse out, clean the connections and make sure the holder and wires in and out are good.

While you are checking wiring, remove, clean, and tighten all battery connections. Especially the start battery. Maybe also have a look at the connections behind the main battery switch too.

[colliejo1]

Thanks moonlighter. We might be in the long haul on this one because I cant seem to consistently reproduce the problem.
I went down to the boat a week ago to prep for a trip. Fired up both engines and went to gas up the boat. No flashing hours or anything odd so I was beginning to like the low voltage theory since the boat has been sitting on a charger for a week
I pulled back to my slip and proceeded to replace the backbone with single piece back bone simply because i had already purchased it. I also checked two power wires (+ &-) for the network and the (-) wire pulled right out of its crimp. I re-crimped, cleaned and secured the power wires. I looked around at all my other connection and didn't see anything corroded or loose.

Left out for the day with no blinking and within an hour it was blinking again. A few hours later I noticed it has gone back to a solid hour reading. Again all very odd and inconsistent.

I did notice the following. My N2K backbone isn't powered directly. the power wire that I mentioned above goes into the Raymarine Seatalk ng rail and out of that is a data/power cable which goes from the Seatalk ng to the backbone. Should that N2K rail be powered directly? The seatalk cable has to be there to communicate with the chart plotter but maybe its being taxed too hard? the power wires for the seatalk rail are tiny, maybe 18 gauge. The network is fairly large, two MFDs, autopilot and its several end devices, sonar module, radar, the suzuki gauges.
What do you think about, as an experiment, powering the N2K rail directly and removing the seatalk cable to see if it remedies the problem. I will temporarily lose fuel economy but not that big of a deal

As a side note I need to call Raymarine and make sure I wont backfeed power to the seatalk ng when I reinstall the cable.

[Moonlighter]

Raymarine Seatalk is something I know nothing about.

You need to be careful that the connection between the NMEA2000 network and the Raymarine network (if that is what it is) does not also feed power into the NMEA2000 network... and also, I dont know how the Raymarine network SHOULD be connected to the NMEA2000 section....

And you also need to look carefully at the NMEA2000 network setup - should have a terminating resistor at each end of the network. A network that is not correctly terminated WILL HAVE DATA LOSS issues like you are experiencing.

Anyway, the interconnection between these two network technologies, and how the N2K network is terminated, are something that you may need to get expert local advice about. I cannot help in that regard. I would be concerned to ensure that networks are correctly terminated.

Most Suzuki networks are powered via a connection to a spare + bullet connector in the gauge harness behind the dash - which means the network turns on and off with the key. Neg just goes to neg busbar. Or, you can just connect + and - to a switch. The C-10 gauges get operating power from their connection to the network. So when the network has power, the gauges turn on. And vice versa.

You could try separating the 2 networks and then powering the Suzuki network as I described above, and ensure that the network is properly terminated and set up.

It should be set up to look like this, and I use the abbreviation TR to designate where the terminating resistor goes:

TR - T - T - T - T - TR

with however many T’s needed - one T per device, and one extra for power.

NMEA2000 setup Rules:

- Power should be connected to a T close as possible to the middle of the group of T’s.
- devices (meaning displays, engine interfaces, anything else) must only ever be connected to the “leg” part of the T, never to the cross part.
- T’s connect directly to each other cross part to cross part, or, a extension cable that runs from cross part to the cross part of next T. Devices MUST NOT BE CONNECTED to cross part of T’s.
- MUST BE A TERMINATING RESISTOR at each end of the backbone, to close off the remaining open end of the end T’s.

[colliejo1]

Im going try separating the networks, seems like the best way to narrow down where the problem could be.
*disclaimer* I didnt wire this boat

I have a technical clarification from your description of powering the Suzuki network above
my current setup is TR-T-T-T-T-T-TR with the 5 Ts being as follows
Seatalk(ST)-Engine Interface-Engine Interface-C10-C10 -(Abbreviating to Tst-Te-Te-Tc-Tc)
I have a master electronics switch that powers on my gauges and all other electronics. In other words, if I only turn the key on, the gauges do NOT power up. On that basis, I assume that the network and gauges are powered thru the ST cable.
The easiest way to tell will be to remove the ST cable and see what happens but I'm not at the boat currently.
Once I do that my network would be TR-Te-Te-Tc-Tc-TR, So I do NOT need to add in another T for power but rather locate the power bullets in the gauge harness and wire that up? Do I understand that correctly?
Do you happen to know the colors of the power wires for the network or where I can find a wiring diagram?

[Harper]

Have a look at this, and see if it is helpful to your situation. https://www.raymarine.com/view/index-id=400.html

[Moonlighter]

It does sound like the network is powered via the ST connection. There appears ro be no other option. And as you say, you will soon find out for sure when you disconnect the ST from its T.

If you remove the ST cable you can attach the NMEA2000 power node to that T. You DO need a separate T for the power node. (Note I have heard of special terminating resistors that incorporate a power connection as well).

This is the usual power node required. Any NMEA2000 power node will do the job - made by the likes of Navico, Garmin, Maretron etc.

https://www.brownspoint.com/store/pc...e-38p63567.htm

If you determine that currently, the N2K network power is coming via the ST connection, you will need to act carefully before reconnecting the ST to the N2K side - N2K networks must only have 1 power supply, and if you leave the new N2K power node connected and then add back an extra T and the ST connection, you then have 2 x power supples and that is NOT acceptable.

There may be a way to solve that by using a Garmin power isolating T to separate the 2 power supplies.

So if the N2K network performance is stable after disconnecting ST and adding the normal N2K power node, you could go down that route when reconnecting.

https://www.brownspoint.com/store/pc...r-38p76434.htm

[colliejo1]

Closing the loop here incase anyone else has this same problem. The issue does appear to be related to the Raymarine N2K cable from the MFD to the gauges. As a test I ran a dedicated power to the gauges and disconnected the Raymarine Cable. I lost MPG and engine data to the MFD but oh well. First 2 trips I had no issues, So I purchased a new Raymarine cable and switch it back, next trip the problem repeated, so I switched back to the dedicated power and now 8 trips over about 70 hours the problem has yet to repeat itself.