Yanmar occasionally won't start, then does.

[akprb]

Thanks guys, that's the answer! 17 years ago same prob on our cat and a Yanmar guy added second relay to each as you describe.

Rough schematic anyone?

[olepedersen]

Sailor chick has it right.Typical yanmar problem, they could well have learnt it from Lucas ha ha

[daletournier]

Last time I used a more robust solonoid

https://www.westmarine.com/buy/cole-...37?recordNum=3

Ive also used the little 30amp auto relays that sailorchic mentioned, they work fine.
I cant remember the exact wiring but there are diagrams on google, its very common.

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[dlymn]

Adding a relay sounds like something an electrician does to make a 10 minute job last an hour. If you short across the starter lead to the solenoid lead it will start every time and this proves that you just have corrosion in one connector. Just string a wire from the ignition switch to the solenoid. the only problem is knowing which terminal ro connect to on the ignition switch. A multimeter will help there. one complication might be that the original might be red at the solenoid but white at the switch. A wiring diagram will help here.

[Ndavies]

I had (still have) the same problem on my 4JH2-TE. I checked all connections, replaced the starter and solenoid, relay (which is an option), and more recently the ignition switch. Nothing really improved anything - sometimes it starts first click, other times it clicks. So I wired in a second heavy duty ignition push button switch directly to the solenoid. If the key doesn't start it first time, I use the push button. I have heard this is a common issue and likely due to undersized wiring. My fix is not the ideal, but works!

[daletournier]

Originally Posted by dlymn

Adding a relay sounds like something an electrician does to make a 10 minute job last an hour. If you short across the starter lead to the solenoid lead it will start every time and this proves that you just have corrosion in one connector. Just string a wire from the ignition switch to the solenoid. the only problem is knowing which terminal ro connect to on the ignition switch. A multimeter will help there. one complication might be that the original might be red at the solenoid but white at the switch. A wiring diagram will help here.

The run from the ignition switch to the starter is often to long with to smaller gauge wire therefore the voltage drop is relatively high. When new there's still enough but it doesn't take much in the way of a very little corrosion etc to cause the problem. Sure you can replace the wire with a greater gauge but its easier to add the relay which effectively does what your saying. The relay takes very little current to energize and is very reliable.

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[akprb]

Yanmar Intermittent Starting - TOSCA

Yup! Googled "Yanmar starter extra relay" and plenty of sites describing precisely! Thanks all!

Going to clean all connections today and first chance add this little baby ��

[Geek_Guy]

I'm sure a relay would be a cool fix. But just taking out the stupid connector was definitely a laymans job. The wires are all color coded. So snip both sides. Take a little piece of wire and couple wire junctions. Crimp. Done.

But that isn't all. My idiot lights immediately started working as well. I probably spent 3 hours tracing and changing bulbs. Only loosing lots of hair. To accidentally discover that it was the stupid connection.

[dlymn]

Originally Posted by daletournier

The run from the ignition switch to the starter is often to long with to smaller gauge wire therefore the voltage drop is relatively high. When new there's still enough but it doesn't take much in the way of a very little corrosion etc to cause the problem. Sure you can replace the wire with a greater gauge but its easier to add the relay which effectively does what your saying. The relay takes very little current to energize and is very reliable.

Sent from my vivo Y35 using Cruisers Sailing Forum mobile app

Adding a relay is really just adding an extra wire. You find the solenoid wire on the ignition, string a wire from there to a relay, and then take a wire off the starter lead as your power source. That is more or less the same as stringing a wire from the switch to the solenoid and then putting another switch in the new wire. However, I do accept that on some boats, the run from the motor to switch is long. The original wiring worked over that distance, it's just that the connectors along that wire tend to corrode and eventually reduce the available current.

[Symphony]

I had the same problem, and I also found the suggestions to add a pony relay. But first I measured the voltage drop and it was not that much. I got a little deeper and found that the wire connecting the solenoid to the starter was fairly loose, and it is hidden on the backside of the solenoid/ starter against the engine block, so it is very hard to see. I had to remove the solenoid to check it. Once I fixed that connection everything has worked fine And I did not need to add the complication of another relay.

[Privilege]

So having read this thread, I was motivated into action to address my sometimes starts/sometimes doesn't JH4. In the past, I've sometimes had to rev the starboard engine to increase the voltage before the port engine would start. I purchased a relay from a local car shop and installed it. The wiring took me 15 minutes and the install took me 30. First I disconnected the wire that runs from the Yanmar panel to the solenoid. It's easy to find, it comes straight from the wiring loom and is probably the only small wire on there. I connected it to the positive side of a piezo buzzer with the negative side of the buzzer going to ground. I wanted to be sure that the start key wiring was not the issue. You can get the same answer with a mutli-meter but I couldn't see the meter and turn the switch at the same time. All was well with the start key and the buzzer sounded when the key was turned.
I then wired the relay as per the diagram below. A very easy process...I turned the key and voila, success! The engine started first time, every time. It's such a relief to have this niggling problem sorted with a $5 fix. Thanks to sailorchic and everyone on the thread. You rock.
[ATTACH][ATTACH][/ATTACH][/ATTACH]

[Symphony]

thanks to everyone who added pictures or diagrams.

[sailorboy1]

Originally Posted by akprb

Symptoms. Yanmar 4j series starts 90% one turn of the key. 10% turn key, nada.

Wait a sec, turn....turn.....vroom. (May be one extra turn or up to three but does start.

Disconcerting.

Fresh start battery, new starter and solenoid last year (swapped out old one just to be safe and that solenoid checked out good)

Replaces Yanmar ignition switch which seemed to help.

On old boat we had similar issue and I recall installing secondary relays as the voltage drop to the solenoid was thought to be to great and that solved.

Anyone have similar issue??????

Side note, we're in Bimini! Say hello :-)

I had the same problem for a couple of years and finally figured out it was the secondary relay had a wire against a hose and must have an open. I moved the wire and also installed s bypass start switch right at the engine. Since then the engine has always started and I've never needed the by pass switch of course

[SailorHarry]

You do not need to put another solenoid in the starter circuit. The problem is most probably a poor connection in one of the multi-conductor connectors in the panel to engine wiring harness--as mentioned by several others already. We had the same problem, and I cured it by running a 10AWG conductor from the key start switch to the starter solenoid (the solenoid on the starter motor). Problem solved for the cost of a few feet of wire and two ring connectors.

[Geek_Guy]

But there are two wires in the mix. One to feed the 12V to the panel, and one to bring it back to the starter. I did as has been mentioned and ran a new wire from the panel to the starter. But still had problems. I was also having problems with the feed from battery/wiring to the panel. Further I had lots of other odd inexplicable issues with the idiot lights and such. Because all that goes through those connectors. I finally got fed up with the issues and spent a couple hours cutting out the connectors. As I said previously this not only fixed the starting problems but made all the gauges and lights work consistently. So the benefits were way beyond just the starting thing. Though admittedly that was the most irritating.

So while the relay will fix the starting thing and it is probably a cool solution. I feel you'll be way ahead of several things if you get rid of that connection.