Yanmar start button problem

[Exile]

Originally Posted by 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. * * *

Replacing the key switch plus separate starter button set-up with just a key switch that does both may be a good idea. I actually have just that on a separate start circuit inside the cabin which always works, regardless of whether the starter circuit at the helm decides to work or not. The latter has worked intermittently since I've owned the boat (15 yrs), and has defied most of the remedies I've tried over the years that are outlined in this and other threads I've read along the way.

My engine is a 80hp Westerbeke, fwiw, but the symptoms are similar. The engine either starts immediately or nothing, nada, zip -- no clicking, zero. But sometimes if I push the start button repeatedly it will fire, other times not and I have to use the downstairs start key. Also doesn't seem heat-dependent which seems rather odd if there is resistance somewhere in the (helm) start circuit.

The one suggestion I have not yet tried is the relay. A mistake perhaps, but I've tried running heavier gauge (10g) wire directly from the starter solenoid to the helm push-button switch and confirmed the same amount of voltage drop (~10.5v) as the existing wire whether the engine starts or not. This is with the red wire that supplies V to the panel key, as well as the white wire which sends current from the push button back down to the starter solenoid. So perhaps, as you suggest, the problem lies somewhere behind the instrument panel, i.e. in the daisy chain wiring between the key and the push button. I've cleaned all of this up as well, but with so many connections (incl. individual lights for each instrument) perhaps this is where the fault lies. It should entail just a matter of replacing the switch and then moving the white wire over.

[alibaba508]

Thanks everyone for all the useful suggestions. I have tried most of them, and eliminated most of them, ie new relay, new starter button etc. Seems a common problem with Yanmar.

What is difficult to understand is that when I fitted a new heavier duty cable from the start button to the solenoid, all problems were immediately fixed BUT only for 3 months. Now its back again.

There is obviously a voltage drop somewhere, and I'll use the above suggestions to trace it.
I particularly like the reply with "an ohm here and an ohm there- remember you only have 12v" Nice.

[sailorboy1]

A relay hardy needs any power

Have you checked the primary power wiring that goes to the relay and then the starter?

If you have a house and start battery, does it matter which is being used?

[Martkimwat]

Originally Posted by 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.

Yes, but it's not sitting in a salt laden atmosphere all the time like your boat is (often only a few inches above the bilge which on my boat always has a little water in it) It's also the reason a car type ignition switch is not fitted, it's not made for exposure to salt laden air.

[hjohnson]

We were having similar issues with our 1GM10. In the end, we’ve solved it, but probably the hard/expensive way (well, short of repowering). We had our starter rebuilt by a local starter & alternator shop, they replaced the brushes and solenoid. We then added a standard Bosch relay between the starter button and the solenoid, and finally, as part of the electrical upgrades aboard, gave the engine a dedicated lead acid starting battery. The starting battery is kept charged up by its own DCC charger off our lithium house bank.

[team karst]

The hard fact is there needs to be more use of a dc voltmeter and much less use of wrenches. Even if u do stumble on an apparent fix, you wont be sure it was the actual cause.
Case in point: I had intermittent start issues, and traced it to the start relay. A new relay fixed it for a few days. The root cause was the flag wire end terminal that slips onto the relay.

[harbin2]

I've run into this problem again so I thought I'd research some recent "posts". Lots of good info. Here is my situation.
I have a 1988 2gm20f. It had a slave solenoid installed when I bought it 10 years ago. In 2018, it was getting harder and harder to start. I almost wrecked the boat in the Bahamas because of it. When I got home, I replaced the slave solenoid. Problem fixed - until recently.
Last summer, the starting issues slowly resumed.
Now, I'm thinking about getting a better "quality" slave solenoid. I'm not sure if that's possible. The one I got in 2018 was from NAPA and was about $25. I believe these things last forever on cars that get lots more use than my boat.
I guess my next what I really need to do is get back in with a meter and a helper to see where I'm dropping voltage.
Wish me "luck".

[Redline452]

Good luck, but if by "slave solenoid" you mean the solenoid on the starter motor which engages the Bendix then applies power to the starter, that is likely NOT the culprit. A small automotive-type cube relay right at the engine, powering the solenoid directly and operated by the keyswitch, resolves (avoids) the voltage drop issues in the start switch and wiring harness (and multiple connectors in said harness). Had that issue on my 2GM20, had it on my 4JH2TE (really long dual wiring haness to the control panel at the helm).

Keyswitch/start button powers relay, relay powers solenoid via 6" of wire (rather than 6++ feet and a switch). Problem solved.

[JimsCAL]

Doubt that its a poor quality relay that is going bad harbin2 and that a "quality" one will fix the issue. Usually they will be either good or bad, not slowly get worse. I suspect it's a bad contact or wire somewhere in the circuit. Troubleshooting with a meter is good step. Try cleaning all connections also.

[ScottRhodes13]

Thought I'd share a solution I came up with for testing the circuitry when I had a similar, intermittent problem.

The difficulty was that whenever I grabbed the bundle of wires near the starter in order to hook up a volt meter, things started working. So I bought one of those trailer wiring harnesses that have LEDs to indicate how your lights are working, and hooked it up to pertinent places in my starter wiring. That allowed me to check which wires were energized without having to touch the wires.

In the end though, after a few times thinking I'd solved the problem only to have it recur, I just pulled the starter, lubricated it, replaced the brushes and bearings, and replaced all the associated wires and connectors. I did not have to replace the expensive starter solenoid, so the total repair was fairly inexpensive (I consider time I spend fixing my boat part of the hobby, so my time is cheap).

Haven't had a problem since.