Yanmar start button problem

[alibaba508]

I have a Yanmar 3GM(f) and have been suffering from start problems. I had intermittent starting when pressing the start button, nothing happening and then after a few presses, it would start. I thought I had solved the problem when I found the wire from the start button to the start relay had been replaced by thinner wire for a section. I replaced this with the appropriate grade wire and all problems were solved for 3 months, start first time every time.
However, the problem has now returned. I have replaced both the start button itself with a heavy duty one, and replaced the relay with a new one.

No change. Does anyone have a similar problem and a fix please?

Thanks

[JimsCAL]

Yanmars are noted for having a starting issue when there is a long wiring run between the panel and the engine. Usual fix is to install a relay at the engine to reduce the current and thus the voltage drop in the wires. Not sure if that is the relay you mention. Problem could also be the starter itself, the starter solenoid, or the wires.

[sailorboy1]

The most likely spot for a problem is at the wiring harness connectors. On my last boat I had to install a jumper wire around the harness plug due to a pin problem in the plug.

[George_SD]

I had this as well and there seem to be a few solutions:
1) check and cleanup all contacts, remove extra splices and improve existing connection as much as possible
2) install a relay on the starter
3) run a new direct wire outside of the harness between starter to the button

I chose the first path, but have the relay ready for install just in case. I've removed male/female connectors on the harness for the control panel/button and soldered the connections, then protected with heat-shrink, removed extra cables between the harness and the button.

https://forums.sailinganarchy.com/in...omment-4629044

https://www.cruisersforum.com/forums...ay-200285.html

[Rumrace]

As a starter motor get aged it draws more current. Solenoid is the usual issue but armature and brushes can heat thinks up if worn.

[stormalong]

Do you hear a click when you press the start button?

If yes, your started needs to be rebuilt or the heavy wiring from the battery to the engine needs to be inspected or the battery is weak.

If no, use a meter at the starter solenoid to see the voltage when you press the start button. That takes two people. If the voltage is below 12 volts the problem is in the start button circuit. Trace backwards from the start solenoid until you find full voltage. Just after that point is your problem.

[Gripfast]

Had a similar issue for years. Found the ground lose where it is bolted to the transmission bracket. Tightened the ground, never had another problem with starting.

[CAR54]

Had the same starting problem for years. It wasn’t until I replaced the original 1987 battery cables that had some frayed ends with new tinned professionally made battery cables and wire brushed the terminals on the original battery selector switch that brought starting reliability to 99.95% for two years now on my Yanmar 2GM20F engine.

[SVPP]

Also Do you have earth leakage when you press the starter? Check the insulation on the solenoid around the pos and neg terminals, they are pretty close together.

What are the voltage readings at different parts of the circuit when you press the starter? As mentioned earlier

You will need to make a diagram of the circuit the enlist the help of a second person to do it accurately

Once you have those figures you will have isolated the problem.

Don’t go ripping parts off your engine and start randomly cleaning (loosening) things until you have done this.

Your multimeter is you best friend - or only friend in my case

[Redline452]

Check the voltage at the solenoid when it isn't starting. If less than 10V, the solenoid pulls in enough to engage the Bendix, but does not hit bottom to make the electrical connection. I installed a 1" automotive-type cube relay at the engine (next to a couple of others for the engine blower etc), activated by the start switch, which then powers the solenoid. End of problems.

[Lemsteraak]

Simple fix

There is a fuse and holder that corrodes. Clean it and you are good to go and will get more voltage to the solenoid. Check the wiring diagram and if I remember right it is under the heat exchanger. Most often it is wrapped up with the wires.

[Lemsteraak]

Wish I could tell you I figured it out myself. Sometimes old guys know stuff.

https://www.youtube.com/watch?v=T0vRVSBnCj8

[billgewater]

I have a 1 GM (not a 3 GM). It has a key on the panel plus a press starter button. I can't see why you could not use a standard starter switch as used on cars. These two switches and the associated wiring looms are the usual culprits with intermittent starting. However, when I had problems it was easier to install a relay at the starter solenoid. The relay cost under $7 AUS and the press switch cost over $20. I am of Scottish descent.
The starter motor on the 1 Gm and possibly others is a Mitsubishi product, so if it needs replacing you can avoid the normal Yanmar prices. These starter motors are really well built and it is fairly rare that they should fail. Consider your own car which is often started twice per day and has not had a starter failure in decades.

[sailorboy1]

On my current 4jh3 the problem was a frayed wire to the relay. Couldnt fix so cut those wires and installed a different automotive relay. But 3+years since and no problems.

[Howler]

I had the same engine and same problem. The run from the starter button at the helm to the starter motor was so long that current was lost along the way. As other posts indicated, all it took was adding a relay. You indicate you already have a relay so maybe it's defective or you're encountering one of the other causes posted above.

Before solving it, to get home, we used a jumper cable right at the starter motor. Disclaimer: This is not a recommended procedure. Use it at your own risk.