SMIS stops working when Lowrance powered up

[bchief803]

For the last several trips the SMIS blanks out as soon as I power up my Lowrance ELITE 9ti. It was working fine, but now I have to restore defaults and go through setup to get it to work after using the Lowrance. If I leave plotter off, SMIS works fine and shows all data, but as soon as the plotter boots up, the SMIS geeks out and stops showing engine data. It does contito show speed and depth. Does anyone have any clue what would cause this?

[Murray]

https://www.suzukioutboardforum.com/...a2000-networks

Some reading material. The resident expert will want/need your engine year and interface software edition.

[bchief803]

2019 df200a. I am unsure of what edition software is on the network. I bought the boat from original owner a couple months ago.

[Moonlighter]

Sounds voltage related?? Step 1 is to check batteries and the connections to be 100% sure they are clean and tight. And the batteries are fully charged up.

Have you tried starting the Lowrance up first, then starting the engine to activate the gauges? What happens then?

Also when you say SMIS gauges, are you referring to the Suzuki C-10 digital display or the Suzuki SMG4 digital display? They are similar but the SMG4 has rounded corners. If you arent sure, do a google and find photos so you can let us know for sure which gauges you have, as they operate quite differently.

[bchief803]

Sounds voltage related?? Step 1 is to check batteries and the connections to be 100% sure they are clean and tight. And the batteries are fully charged up.

Have you tried starting the Lowrance up first, then starting the engine to activate the gauges? What happens then?

Also when you say SMIS gauges, are you referring to the Suzuki C-10 digital display or the Suzuki SMG4 digital display? They are similar but the SMG4 has rounded corners. If you arent sure, do a google and find photos so you can let us know for sure which gauges you have, as they operate quite differently.

Terminals are clean and tight and voltage looks good. If Lowrance is on first, the gauge will boot up when cranking, but is blanked out. Once I restore defaults it works fine as long as Lowrance is off. It is the Square display (fairly sharp corners). This seems to have started after I added fuel and went through process of updating fuel on the display when it first boots up and asks if fuel has been added. It was doing fine before then with or without Lowrance running.

[Moonlighter]

Something is definitely wrong.

I am wondering about your network backbone setup. Its critical this is done right, or there will be problems.

When you added the Lowrance to the network, exactly what did you do?

You SHOULD have added an extra network T to the backbone and connected the Lowrance to that T with a drop cable.

With the C10 plus the Lowrance on the network, your backbone must have 4 x T’s in a line like this: TTTT all connected at the cross. The end T’s must have their open ends closed off with a terminating resistor (therefore there will be 2 x TR’s).

4 T’s are required, one each for:
- The suzuki engine interface
- the network power supply node
- the C10 and
- the Lowrance display.

Please verify that the backbone is set up correctly as described above. There is only one correct way to do this.

Take photos if any doubt.

If you 100% verify that the backbone is set up correctly, then I am thinking that it may be a bad network T or cable. Bad T’s and cables sometimes happen. So try swapping out the T first. You could also try a different drop cable between the Lowrance and the T as well.

If after that it still happens, the evidence is kinda pointing to the Lowrance’s network circuity. If you know someone else with a Lowrance display you could swap it and see if it works. If it does work then, you should be able to contact Lowrance and ask for a warranty replacement.

[bchief803]

Something is definitely wrong.

I am wondering about your network backbone setup. Its critical this is done right, or there will be problems.

When you added the Lowrance to the network, exactly what did you do?

You SHOULD have added an extra network T to the backbone and connected the Lowrance to that T with a drop cable.

With the C10 plus the Lowrance on the network, your backbone must have 4 x T’s in a line like this: TTTT all connected at the cross. The end T’s must have their open ends closed off with a terminating resistor (therefore there will be 2 x TR’s).

4 T’s are required, one each for:
- The suzuki engine interface
- the network power supply node
- the C10 and
- the Lowrance display.

Please verify that the backbone is set up correctly as described above. There is only one correct way to do this.

Take photos if any doubt.

If you 100% verify that the backbone is set up correctly, then I am thinking that it may be a bad network T or cable. Bad T’s and cables sometimes happen. So try swapping out the T first. You could also try a different drop cable between the Lowrance and the T as well.

If after that it still happens, the evidence is kinda pointing to the Lowrance’s network circuity. If you know someone else with a Lowrance display you could swap it and see if it works. If it does work then, you should be able to contact Lowrance and ask for a warranty replacement.

I greatly appreciate the input. There are four Ts. I had read something previously about them and checked to make sure they were inline and tight. The installation was done prior to me purchasing the boat and was complete at dealership. Would it be changing out just the T itself or an entire cable? It is just weird to me that it worked great prior to updating fuel on startup. I'm thinking I will just go ahead and replace Ts and go from there. I greatly appreciate you taking the time to help out.