Yanmar starter solenoid/button problems

vyv_cox

vyv_cox

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My starter button for Yanmar 3GM30F has gradually become more and more erratic. When the batteries are fully charged the engine usually starts first push but if they are a little low it is something of a lottery as to when it will go, sometimes up to 10 presses before one takes. I have noticed that quite a current flow is being registered on the ammeter, so something is happening.

I have read here that there is a fuse hidden beneath the wiring loom, the wiring diagram in my operator's manual and workshop manulal both show it, 30 A in the heavy red cable that supplies the key switch and the starter button. Having decided that there must be some resistance in the fuse holder I have spent a couple of hours this morning trying to find it, with no success. I did find a surprising number of spade and barrel joints in the white solenoid wire but no fuse in the red. Has anyone found it?

Having opened every joint and connector I could find, none the slightest bit corroded, I put them all back together and the engine started first time. With luck I have solved the problem but I would love to find that fuse.

All major cables, both positive and earth, and their connections, are fine.
 
Your problem is quite common and has been the subject of many remedies on this and other forums. In my own case I ran a new thicker wire directly from the starter switch to the solenoid and for two seasons it seemed to do the trick. I then found when the engine was warm, the problem appeared to re-emerge and I believed that the heat in the engine compartment was increasing the resistance in the heavy connections either at the start battery or the solenoid so they were all cleaned up etc and all was well again for a season.
Last time I had the boat out-the problem re-emerged! I too am baffled and never found the fuse-holder. I wait with interest to see what else is proposed by others so afflicted.
 
I had exactly the same problem with my 4jh3. The cable route from the start switch to the starter solenoid was long and tortuous with quite a few connectors and not many volts getting through. I fitted a solenoid close to the starter motor activated by the start switch lead and connected to a clean 12v supply. Seems to have solved the problem completely.
 
Well, if a 1GM is anything to go by, which it probably is:
almost anything you do will solve the problem for a while. One of those deeply frustrating intermittent faults.

You mention electrical connections and, especially, earths. For the benefit of anyone new to this game, making sure these are all good is the best first move.

On the 1GM that fuse is close to the in-line connecting plug which carries +12v and neutral for the starting circuit, it's just a little way towards the engine. It's a small plastic box about 4cm long and about 2 cm wide and about a fuse thick, and is covered with the same grey paint that coats the engine so no wonder it's hard to find. If you open it up you will find the active fuse and a spare fuse. Cleaning up the fuse and its contacts will solve the problem just long enough to confuse you and convince you that you have found a permanent solution. The problem will then reappear.

Some users have reported a high resistance inside the push button starter switch. I found an intermittent high resistance in the "ignition" keyswitch, which is impossible to open up, although if you do open it up, catch the springs and ball bearings which will fly out, and clean up the contacts, the problem may be solved. For a while.

I am given to understand that a slightly low voltage entering the solenoid will result in slight burning of the contacts (?) which will give intermittent starting. Thus, expensively replacing the solenoid will give a cure. Temporarily. (Incidentally, it's a mechanical switch as well as a relay, but I'm sure you can explain this better than I can.)

The in-line connector mentioned above might be another source of poor contacts so opening this and dosing with contact cleaner could help.

The starter motor itself can be blamed. The consensus seems to be that this is the least likely source of the problem.

If I get any more trouble with this **** thing I will be fitting a relay in the circuit, as mentioned in other posts.
 
I have this problem every now and then on my 1GM10.

I've stood there scratching my head thinking 'Cant be low batteries , i've just been motoring for 10 hrs!'
Then at the next push of the starter button it goes immeadiately as if nothing is wrong.

Thanks for some leads.
 
It is a fairly common problem. Installing a relay (sometimes called a helper relay) is usually a permanent fix.
 
For me on a 3GM30, the same problem was solved with Contalube on bothe the connector at the switch panel but also the hidden one near the starter. Never found a fuse! :)
 
Slightly off topic but maybe of interest/relevant, our chandlery has started selling a spray called 'battery connection protector' or some such. It claims to provide a waterproof seal and improve conductivity to all electrical connections. It claims to displace water also but is different to wd40. Has anyone experience of a product like this and would there be any likely drawbacks ? My own electrical gremlin at the engine control panel is an erratic temperature gauge which is likely due to a poor connection somewhere. Have been thinking of cleaning all connections thoroughly (maybe a bit of copper grease) and then spraying them all with this stuff but do not want to do it if it is impossible to get off.
 
blackbeard said:
On the 1GM that fuse is close to the in-line connecting plug which carries +12v and neutral for the starting circuit, it's just a little way towards the engine. It's a small plastic box about 4cm long and about 2 cm wide and about a fuse thick, and is covered with the same grey paint that coats the engine so no wonder it's hard to find. If you open it up you will find the active fuse and a spare fuse. Cleaning up the fuse and its contacts will solve the problem just long enough to confuse you and convince you that you have found a permanent solution. The problem will then reappear.
Click to expand...

I found that fuse but it is clearly not the one I am talking about. It has several thin wires into it, whereas the one in the manual is a 30 amp fuse in a heavy red wire. I didn't bother disturbing mine.

This is all very similar to the problem any air-cooled VW van owners will recognise. Very long lengths of cable from engine to cab and back, probably several connectors and a starter motor under the van where it gets lots of salty spray. My solution was to take an additional lead from the solenoid connector into the engine compartment. If it didn't start, touch the wire onto the battery positive. Never failed.
 
vyv_cox said:
I found that fuse but it is clearly not the one I am talking about. It has several thin wires into it, whereas the one in the manual is a 30 amp fuse in a heavy red wire. I didn't bother disturbing mine.
Click to expand...
Now I'm really confused! the fuse I found is the 30 A one with the thick-ish red wire as shown in the GM manual. No idea where a fuse with several thin wires comes into it, but then, my engine is just a 1GM made about 15 years ago.

I like the idea of the extra wire touching the battery +12v if all else fails. Presumably fitting a relay does essentially the same thing.
 
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