Yammer, won't start without arcing

[RebeccaM]

My husband is getting close to the end of his patience with one of our GM30FC engines. It stopped turning over each time we tried to start it, and got so bad, that it wouldn't start unless he went below and arc'd it. He thought he'd found the issue with some corrosion on the starter solinode, so cleaned connections. Now, ignition switch won't turn on, so no alarm or sensors come on. It will still start when arc'd but nothing else. He feels like something isn't plugged in, but has traced all lines and tested them all back to the starter. Any ideas? I really would like to see him enjoy his time on the water!

[SailsTeam]

What do you mean arc'd?

[RebeccaM]

Originally Posted by RebeccaM

My husband is getting close to the end of his patience with one of our GM30FC engines. It stopped turning over each time we tried to start it, and got so bad, that it wouldn't start unless he went below and arc'd it. He thought he'd found the issue with some corrosion on the starter solinode, so cleaned connections. Now, ignition switch won't turn on, so no alarm or sensors come on. It will still start when arc'd but nothing else. He feels like something isn't plugged in, but has traced all lines and tested them all back to the starter. Any ideas? I really would like to see him enjoy his time on the water!

Ok, so here's the good news! He says I posted too soon...after weeks of fiddling with this engine, he has it working! He is feeling a bit frustrated, turns out he had a wire crossed! You know how life does that to you, complain about someone taking too long and turn around and there they come? Patience is a virtue we are still seeking some work on! Fair winds!

[RebeccaM]

Originally Posted by SailsTeam

What do you mean arc'd?

My mechanical vocabulary is limited, it's also "shorting". Jumping between the solenoid and hot battery.

[ColinIOM]

Hi, I take it you are just shorting across the two big solenoid connections probably using a screwdriver? If you are then the engine will likely start and run but I don't think your alternator will be charging, there is also possibility you will have damaged the alternator diodes irreversibly.
Regarding faultfinding, you may already know this so sorry for stating the obvious) It sounds like an electrical problem with your ignition switch or the power that supplies it.

So you need to trace the power supply from:-
The Batteries to, the main isolator switch, then to the ignition switch, then to the start button, then the starter solenoid. (You already know there is main power (big cables) to the starter solenoid, but I am talking about the control side of the solenoid, the small wires)

If you are up to fault finding it yourself, if not, get an electrician or someone who is to help you.
Then you should test to see if there is any power (around 12.5 volts dc) at the ignition switch when in the off position (there should be, at least to one of the connections) if not, look for and check fuses (put the negative wire of your test meter to a known good battery earth, maybe even directly to the battery itself)
If there is good voltage,
Then switch the ignition on, then check again that the power should be on at least one more terminal and feeding one side of the start switch button (this is all behind the engine panel)
Again, (if not, or the voltage is considerably lower replace the switch) If there is voltage,
Then press the start button while you test to see if the power is now on both sides of the start switch, again there should be around the same voltage, (if not, or considerably lower then replace the button switch)
Again, If there is good voltage,
Then while the start button is pressed, test to see if there is power at the starter solenoid, beware, the solenoid must be grounded to battery earth or it may have its own negative supply (if there is power, listen to see if you can hear the solenoid "pulling in with a Click" if it is pulling in but not turning the engine then its change the solenoid, or if there is power but not energising ( pulling in) then replace the solenoid.

I hope this helps,
All the best
Colin

[topmast]

Some understanding of stuff helps. Guy I know just melted his jumper cables by connecting to the same positive terminal on the dead battery.

[ColinIOM]

Also please note that sometimes there are "circuit breakers" designed to protect system, when they trip, sometimes they just need reseting, if they continually trip out, there is either a fault in your circuit or with the breaker itself
Colin

[captstu]

I sympathize with you. Embarrassed to say how many times I've groussed about a problem only to find out it was mine!

However, the inability to start a 3GM or 3HM Yanmar remotely is a fairly common problem. The wire length and yanmar plug/cable between the ignition panel and the engine harness are marginal.

When I do a delivery - or own a small yanmar - I place a waterproof heavy duty pushbutton available from West in the circuit between the heavy wire from the battery and the light wire from the switch. This allows me to easily crank the engine from the engine compartment rather than arcing the starter with a screw driver.

Safer and easier. I've owned a dozen or so small Yanmars (or delivered boats with them) and had this failure 3 or 4 times.

The fact that this fault was not Yanmar's problem doesn't stop the solution from working.

[Elie]

In my opinion, the problem is quite simple: The starting key, is not feeding the secondary circuit of the solenoid switch. That esplains also the fact that threr are problems with electrical thing in the control pannel of the engine. You must check first if there is any power reaching the starting switch(the physical key!). If there is 12 volts, then the switch is dead and need be renewed.
If no 12 volt is present, then there are 2 possibilities : the feed of this key switch is the problem(most probable) or the wire between the key switch and the solenoid is broken, corroded, etc.. Easy enough to findout. Good luck.