Suzuki Key Switch

[Egretboy]

My 2016 200 AP Suzuki Key switch has constant power to it from my starting battery when my main power switch is in the off position. I was told this is to store the fuel data. If that lead it put to the switch so when i'm in the off position everything has no power even the key switch will I loose my fuel data seasonal fuel engine hours data etc.
If not why does the key switch need to be wired to a constant source or directly to the battery? Please explain

[Moonlighter]

No the engine won't lose fuel data if the power is cut, whoever wired it that way and told you that reason is incorrect. It should be wired so that when the battery master is turned off, the ignition power is also off.

Who told you that???

The Suzuki network memory is very similar to "flash" memory like a memory stick. It retains all data even when powered off.

The only thing that is normally wired direct to the battery and stays powered even when the master switch is off, is the music system yellow wire for its station memory.

[Egretboy]

Thanks
That clears things up. I was told by the boat manufacture that's the way it's done. Not sure why either didn't make sense. Is there any other reason that would require it to be wired to a constant source? Is there anything in the network that would require it? Fluid Level sensor or any other crazy thing by chance?
I will test the theory and report back to ya to see anything changes. Just to confirm your information.
Thanks
Phil

[Egretboy]

I was told the constant wire is for the ECU or CPU to prevent voltage spikes when turning on & off power to the motor.

[Moonlighter]

Every other boat is wired so the main battery switch turns everything off.

No there's nothing else on the network that would require constant power to retain settings etc. it's simply wrong, what you've been told.

Talk to your Suzuki dealer rather than the boat manufacturer.

[Egretboy]

I spoke to my local dealer which is a big re power company and a different source than my boat manufacture. They took the time to explain it.

They said according to the book from Suzuki the ignition switch should be wired to a constant 12 volt source (starting battery)to protect the outboards computer from voltage spikes. If you choose to wire it directly to the switch so everything off when your main switch is in the off position then you can. If you have a ECU problem under warranty and it not wired to the constant source the Suzuki may void your claim.

Please post a rigging manual that shows this if you like. I would love to see it shown in writing with pictures of the harness connections the correct way from Suzuki Marine.

[Moonlighter]

I am consulting with spe******ts and will let you know when I get further information.

But I can assure you that no data is lost on any network device when the battery master switch is turned off, or indeed, when the battery is totally disconnected. I do this (turn off battery master switch) all the time on my boat so I speak from personal experience, not from theory.

The proposition that you have put forward also begs the question: what happens if a wiring issue/fault arises in the engine harness? Not being connected thru a master switch means no ability to quickly cut power and potentially save a fire or worse from happening. Other than by getting the tools out and disconnecting power from the battery lugs. Which takes time.

I suspect there is some confusion/misunderstanding with what is being stated, but we will see when we get the expert advice back.

[internationalmarinemike]

I was speaking with Grant on this tonight. He as usual is 100 percent correct. Here are the wiring diagrams for both the AP and the Mechanical Motors for your review.

[Moonlighter]

Thanks Mike, and welcome to the forum!

I know you're very busy with your Suzuki dealership and helping members out over on THT, but hope you find time to drop in here occasionally to lend a hand!

Cheers!

[Egretboy]

You are correct in the no data loss.

The question still in hand is why they wanted constant power to the sub battery cable to have the key switch hot when the main battery switch is off.
I've heard yes and no on this due to the ECU having power to it 100% of the time.
Doesn't make sense to me for sure. Any other info would be appreciated.

Thanks
Phil

[Moonlighter]

You've been supplied with info and diagrams by Mike who runs one of the biggest Suzuki dealerships in the US. And, he confirmed what I told you earlier.

I have never heard anyone else suggest wiring it as you say that yours is wired. Either you're misunderstanding what they've told you, or they are telling you incorrect info.

What more do you need??

Tell you what, since your sources are telling YOU differently, how about YOU go and get them to give you THEIR version of the Suzuki wiring diagram and installation instructions and post them here for us to see.

[Egretboy]

Once again thanks for all your help.

[internationalmarinemike]

I have seen dealers do it both ways. We do it the way it is in the rigging manual; the sub battery cable goes directly to the battery not the battery switch.

I spoke to Suzuki Tech Service Manager and they want sub barely cable directly to the battery and not the switch to minimize a voltage drop on the sub battery cable when starting the motor.

Here is how is should be done:

1. When you turn on battery switch you should be able to trim motors up and down from the switch on the motor only (AP Models)

2. When you turn the battery switch on you can trim motor up and down via binnacle and motor switch (Mechanical Motors)

3. When you turn key to on position the gauges will turn on.

When you have batteries off and turn key to on position:

Gauge will turn on and you will get a low voltage warning from gauge.

[Moonlighter]

Now that we are talking just about the sub-battery wire and not the main engine power supply, yes, I too have seen it both ways - sub-battery switch to the main switch or direct to the battery +.

Early days and occasionally now, we heard about the sub-wire being connected to the starter motor instead of the battery, and that has definitely caused low voltage to the ecu issues.

[Egretboy]

Now that we are talking just about the sub-battery wire and not the main engine power supply, yes, I too have seen it both ways - sub-battery switch to the main switch or direct to the battery +.

Early days and occasionally now, we heard about the sub-wire being connected to the starter motor instead of the battery, and that has definitely caused low voltage to the ecu issues.

With all due respect I was talking about the sub battery cable all along for the motor. Guess I should of made it more clear from the start.
I totally understand about not loosing data part.

Thanks Mike for clearing it up for both of us and all that reads this thread.