SMIS Gauge Issue

[Mike S from PA]

Hello,

I have 2 SMIS gauges on my boat. At the beginning of each trip they both work fine. Then sometime into the trip they both stop working and either flash or show RPM's way lower than they actually are. From time to time they will begin working again but last trip once they stopped working they didn't come back on. Even after shutting off the boat and restarting when fishing at various spots.

Any idea of what is wrong?

Thanks, Mike

[Moonlighter]

Could be a few things. Can be hard to pin down strange problems like this.

One is network power supply - it must be a good solid 12V. So check network power connections and make sure they are good. Check the i line fuse holder to the network power (if fitted) and make sure no corrosion.

Next is compatibility between engine and the interface software - can you tell us what year your engine is and what software version interface cable you have? And sometimes this is compounded by compatibility with the SMIS gauge software as well. As an aside the SMIS gauges are problematic with recent year engines.

Do you have any other devices (eg Sonar/GPS screen) on the network? If so what make/model.

Let us know those things and how the power is connected (and how healthy it is) and see how we go from there.

[Mike S from PA]

For some of your answers I'll need to check next time I'm using the boat.

As far as the detail I know, the motor is a 2012 Suzuki DF300.

I have two fish finders in the network. These are a Simrad 12" NSS & Simrad Go7.

I've attached a photo of the NEMA cabling although I'm not sure if it would be a help.

Thanks, Mike

[Moonlighter]

With the engine key turned on, in either of the Simrad menus you can open the netwoek menu/device list and select the Suzuki device, it will show you the software version for the Suzuki interface. For a 2012 year engine it should be V2.9.0.

when your problem happens, do you also lose engine data on the Simrads?

The photo shows nice neat wiring setup in your boat. But it doesnt clearly show the ends of the cluster of network T’s. Is there a terminating resistor fitted to each T on the ends of the cluster?

[Mike S from PA]

Moonlighter,

I plan to head out on the boat Sunday. I'll gather the missing information then and take some extra photos.

I wanted to state in my original post the Simrad units lose all reference to any gauge type data as well. I recently installed a Fell marine wireless kill mob switch device. I can't say I recall the units doing this prior to the install.

How can I check for a good solid 12v?

Thanks, Mike

[Moonlighter]

You need a multimeter to check voltage.

But First, make sure the network power connections are good - by that, I mean find the power node that connects to a T, and trace the wires from it back to where they are connected to power. Undo those connectors, inspect the wires etc for condition, reconnect and tighten.

Given you have had other wiring changes, pay particular attention to the negative connections at the negative busbar and make sure nothing is loose or broken. May have been disturbed when the new item was added. Check the connections back at the battery and battery switch to ensure they are all clean and tight.

And lastly if you have any doubts at all about your battery have them load tested. Auto or battery shops will usually do it for you.

[Mike S from PA]

Hello Moonlighter,

I wasn't successful on checking voltage, connections & the fuse block as I ran out of light. I was able to check the T's and they all are tight. I checked the software version & both are only version 2.4.0 RZ737. See the attached photo.

The gauges did not work from the start of the trip. The following did not work at all RPM's, trim %, fuel flow. Diagnostics said OK & the fuel remaining seemed to be correct. The time of day did not not work on the Simrad units which seems strange.

When I was checking the menu I noticed the Suzuki engine said (unconfigured). See attached photo. I tried to configure and added the proper information. It said configuring but never changed to show the right information like the DF 300.

Thanks, Mike

[Moonlighter]

The software shown as V2.4 in your photos is for the SMIS gauges, not the interface. We need to see the Suzuki engine interface software version.

Despite that, it does sound possible that you have low voltage to the network, one of the symptoms can be that configuring does not “take”. I would be looking at the network power connections, the battery charge and associated cables. As previously said, these systems will not work properly when they are getting low voltage including voltage that does not maintain under load. A corroded connection or internally corroded wire can cause that as well. So you have some work to do to check and if required, fix that issue. There should be a duse holder in the network power + wire, open it, take out the fuse, check the fuse holder and fuse for corrosion, and reinstall.

If you open the Suzuki (engine) device on the device list, what software version does it show? Should be V2.9.0.

Its also possible that we might need to reload the Suzuki engine interface software if it has been corrupted due to a voltage issue. No big issue, its easy, I can help you do that via the Simrad GO unit.

[Mike S from PA]

Moonlighter,

Thanks. Next trip down I'll focus on the electrical portion of the connections and look up the correct software. What voltage should be coming form the battery to consider it clean? 12V + a little?

Thanks, Mike

[Moonlighter]

Should see 12.6/7 from a fully charged battery at the terminals. Over 12v at the gauges.

[Mike S from PA]

Hello Moonlighter,

I was able get some more information from the boat. Both batteries measure 12.55 volts. I could not track the wires back from the network connections to the bus bar. I removed and re-tightened the connections. It appears the software version I'm using is 2.3.0 RR31D (see photo). Same as last time the gauge only show fuel level & nothing else. The gauges don't even switch over to engine trim screen/view when trimming the engine. This time the time of day worked on the Simrad units. I've attached some additional photos. The end of the network looks like it should have a cap on it which it doesn't. I al so attached a photo of the back of the gauges.

Suzuki software.jpgBack of SMIS.jpgEnd Network.jpg

Thanks, Mike

[Moonlighter]

Ok, that photo helps.

The network will not work properly unless it has a terminating resistor at both ends. Its a critical issue. So that open T piece on the end needs to have a terminating resistor fitted as the first priority. Also check the other end and see if it has one fitted.

The rules of NMEA network construction are pretty simple and must be followed:

1. Each end of the network must be terminated with a terminating resistor. (Male at one end, female at the other)
2. Devices must only be connected to the leg of the T’s, NEVER to the cross part.
3. T’s onnect together like this : TTTT with a resistor closing off the open cross piece at each end.
4. No drop cable between a device and its T shall be longer than 6 meters.
5. Best practice is for the network power to be connected to a T half way along the cluster of T’s. The cluster of T’s is called the network backbone. There shall only be 1 T piece connected to power on the backbone.

So check and see it is all like that, and get that terminating resistor installed. Then Check how it works, start the engine on the muffs, see if all data comes thru, and particularly see if the fuel flow looks OK.

We will deal with the wrong interface software version after that, if necessary.

[Mike S from PA]

Hello moonlighter,

I've attached a photo of the other end of the network connections.

Something else to mention. I added the 7" Simrad within the last few months. If memory serves me correctly the gauges were working after I added it. But for the 7" simrad I have the power wires going directly from the back of the simrad to the fuse block. Is that OK?
Other End Network.jpg

Thanks, Mike

[Moonlighter]

Dont be confused - the Simrad and most other displays still need their own power supply to operate. So that is fine. You must have added an extra T piece to the backbone and a network cable between the Simrad and the T - that is how it is done.

The network backbone needs its own power source to drive the network circuitry in each device so they can communicate with each other. Only a few low power consumption things like the C-10 and SMIS gauges also draw their operating power from the network.

That end of the network backbone in your photo looks good - that “cap” on the end T is a terminating resistor, tnere should be one on the other end. Maybe it was loose and just fell off? Or got left off when the Simrad’s T was added?? Regardless, it is vital that it goes back on. Think of the network like the water pipes in your house - if one tap is left wide open, the data flows out the end and is lost and all other taps lose pressure (data) too!

[Mike S from PA]

Moonlighter,

Thanks. I see I have extra terminating resistors at home. Next time I get to the boat i'll add one to the end. If that doesn't work I'll start unhooking the added electronics ( Fell kill Switch, Simrad 7", & I forgot to mention a stereo) one at a time to see if it fixes the issue.

Mike