Suzuki 175 Won't Start

[joffo81]

Hi everyone,

I am after some help to diagnose and solve a problem that is currently intermittent but scary all the same.

Occasionally, when the key is turned, nothing at all happens. No diagnostic lights or beep and no crank of the engine. Of course this first occurred 30km offshore! I switched the batteries, turned the key and still nothing. Wiggled the forward control a few times, back to neutral and nothing. Repeated a few more times then it started as normal.

Obviously there is a loose wire or bad connection somewhere! The fact that there is not even a diagnostic light or sound when the key is turned may help identify the problem. I think I will start by opening up the forward control and check any wires/switches I can see.

Does anyone have any ideas or experienced the same symptoms?

Cheers
Joffo

[552Evo]

How is your key switch set up ?
Is it on a dash or integral to your outboard control.
I'd be checking the key switch itself then the wiring to the rear of the switch.



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[joffo81]

Key is on the rear of the outboard control. I think that's where I will begin. Perhaps the kill switch is playing up even though its never been used?!

[Noelm]

Find the white wire, and make sure it is fully intact, and connected direct to the battery.

[Greg P]

Neutral start switch in the control box possibly on the fritz

[terryc]

could be a fuse on the way out

[Noelm]

Be pretty unusual for a fuse to be "on the way out" fuses blow, or their good, be unlikely for anything in between.

[Flex]

firstly does your motor make all the usual noises at first part key turn? Fuel pump priming etc?
Secondly I'd be tracing voltage to your start relay, determine if it's at the control box or in the motor. Should be quick and easy.
Easy to print off a circuit diagram from a service manual to help,
If it's intermittent sound like dodgy neutral switch or loose cable.

Also check your stack of neutral cables on your motor block. First place stuff generally corrodes/loose.can affect a lot of stuff

Coukd also be your starter/solenoid. Do you hear a click at key turn?

[Owen]

Find the white wire, and make sure it is fully intact, and connected direct to the battery.

What Noelm said
There's a joiner/plug in it between motor & transom
Check there as well.
Seen it happen a couple of times.

[Fed]

I don't think the white wire being connected to the solenoid would give an intermittent loss of power to the helm self tests.

Without a circuit diagram I'd start at the fuses looking for a dodgy blade connection.

Probably limited to visual & physical checking unless you can get it to 'do it's thing' then you could pull out your meter.

A circuit diagram would surely help, is it a late model 4 stroke?

Edit: If it does crank over fine then I doubt it has anything to do with the 'big' wires failing to power up the self tests.

[Dignity]

How old is the motor, I had a suzi which did the same, the kill switch had shrunk back just enough not to make contact,

[scottar]

My money will be on the neutral start switch. Anything you suspect - activate or deactivate as required and see if it produces the same results - put the engine in gear and then turn the key - if it produces the result you have intermittently had then it is a possible cause. If you activate the start in gear protection but it beeps and the diagnostic lights work - it's not the switch. Same with any fuses or joins in wires that you think may be suspect.

[Noelm]

And don't forget, there is a neutral switch on the motor, and control box on most Suzukis.

[Noelm]

Just as a side note, be careful turning the key on a putting it in and out of gear, lots of motors (including Suzuki) utilise this in set sequences to "program" the ECU/EMM (computer) and it has been known to screw up functions by random operation.

[joffo81]

I'm pretty sure the motor is a 2010 model.
Lots of great ideas and information. Thanks everyone for your input so far. I still haven't had a chance to pull anything apart and start checking wires/fuses etc yet but need to get to it soon as I plan to take the boat out mid-week!
I will keep you posted on what I find or don't find.

[Noelm]

OH, and just to be clear, if you do not get a full, clean 12V on the White wire, nothing works, it supplies power to the ECU, it is a very common fault.

[Noelm]

Something I just remembered from trouble shooting a mates Suzuki (175HP) I noticed that when everything was dead, from a bad "white wire" the trim switch on the motor still worked, now, I have not studied the circuit diagram, and really don't know if it's 100% certain that this is a common occurrence, but in one case it was, it just might be a clue in trouble shooting if someone has either a diagram, or experience if this is fact, it appears as if the motor mounted switch gets its power from somewhere else, maybe Moonlighter might know? I will google a bit and see what gives.

[joffo81]

I opened up the control box today and also unplugged and replugged the looms near the control box. Everything appeared to be in order and functional. I lifted the cowl and also had a quick look but nothing stood out as being physically broken. I haven't been able to replicate the symptoms as Scottar suggested. It appears as though the kill switch and neutral switch still allow the diagnostic lights and beeps but the engine just won't turn over. This is slightly different to when the problem occurred at sea.
Fingers crossed all is good as we are heading offshore tomorrow!

[fishingrod]

A friend had symptoms approximately similar to yours on a 115/140hp Suk.

Upon detailed inspection a hidden fuse holder was discovered between the outboard and helm position. It took a while to find as it was not near any of the main loom connectors or plugs. It was actually hidden out of sight under some split loom tube under the gunnels.

The fuse holder didn't like salt and had corroded. Apparently this fuse was an important part of the control box / ignition system. I don't know the colour of the wire the fuse was on as I wasn't involved with the diagnosis. Maybe this fuse is related to the possible white wire issue others are mentioning.

So if you get stranded, carefully trace all your wiring from helm to motor to see if you have a hidden fuse holder or break in this magic white wire.

Cheers
Rod

[scottar]

I opened up the control box today and also unplugged and replugged the looms near the control box. Everything appeared to be in order and functional. I lifted the cowl and also had a quick look but nothing stood out as being physically broken. I haven't been able to replicate the symptoms as Scottar suggested. It appears as though the kill switch and neutral switch still allow the diagnostic lights and beeps but the engine just won't turn over. This is slightly different to when the problem occurred at sea.
Fingers crossed all is good as we are heading offshore tomorrow!

That ascertained, the next step is to unplug the infamous white wire and see if that produces the symptoms. If it does, start hunting for / through joiners and fuse holders as the lads have mentioned.

[Noelm]

Definitely do the White wire check, any Google search will reveal hundreds of problems, exactly the same as yours, I do believe the White wire "system" was not used on later models.

[joffo81]

The southerly blow has put an end to our fishing plans this morning :(
Good thinking Scottar and Noelm. I need to check that white wire! Thanks for the info Rod. Ill follow the wiring along the gunnel and check for extra fuses.