Replacing engine starter switch on a H31

Stu Jackson · Apr 18, 2016

It is so rarely the switch, but it's usually what folks think it is. Check the wiring between the switch and the starter solenoid first. On some boats there is a useless fuse in that wiring.

Benny17441 · Apr 18, 2016

Yes and No. It is simple to replace the starter switch but the switch is likely fine and your problem has to do with old wiring to the solenoid causing a voltage drop. It usually starts as a random "push button and nothing" and then it will become more frequent, it does have to do with the state of charge of the batteries but eventually even freshly charged batteries will not do it. It is a common occurrence in old boats and some not so old and the most used solution is to wire an auxiliary solenoid. Check the archives as there are plenty of posts on this issue.

Ken13559 · Apr 20, 2016

If its a Yanmar engine, check the plug assembly of the cable loom at engine.
That plug has a heck of bad contact every once in a while. Pull plug apart and spray contacts with electric contact cleaners.

RoyS · Apr 20, 2016

This can get expensive. I have the same problem with my Yanmar 2QM15. Over the last few seasons I have replaced the starter push button, key switch, solenoid, and appropriate terminations, all with no improvement. This year I am replacing the wire that feeds the key switch and the wire that returns back to the solenoid with a No. 10 size, hoping to eliminate this problem. If the wire size increase fails then I will try an auxiliary solenoid. I am ashamed of my troubleshooting methods here; always replacing something simple without clear proof of success. I hope you avoid this approach and save your money.

wufibugs · Apr 20, 2016

I did not have the problem, but back when I got my H31 I had heard accusations that Hunter underwired this circuit. I elected to change all the wiring from the cockpit panel and insert an inexpensive solenoid into the system as described in older threads on the subject. Since you need to take down the cover on the aft berth ceiling that shields the pedestal cables in order to pull wires from the cockpit panel, it's a good time to take a look at all of them. I added a fuel gauge at the cockpit panel [whose accuracy under sail is marginal] and replaced the bulbs in the panel idiot lights with LEDs. The ignition key on that panel had been kicked so many times the plastic ignition finally disintegrated. So I moved the ignition key to the salon and replaced it with a more rubust on/off switch at the panel. The key is now just a security device that energizes the switch at the panel. I should have added a indicator light that glows when the bilge pump is on, something that's not obvious unless you are below decks.

Stu Jackson · Apr 20, 2016

IH8,

As you can imagine, this is a recurring question. In most production boats, the wiring between the start button and the starter solenoid is made up of different sections of wire connected with horrible connectors. This is done for the ease of the builders, certainly NOT for the integrity of the connections. Hence, you'll see lots of discussions about wiring harnesses & the connections. Trailer connectors are often used. They should be replaced. If they short out you could end up with a boat that tries to start itself!!! or a fire.

In most cases the wires themselves are OK. Some skippers add yet another solenoid, either because the wires are undersized to begin with, or that has become the go to answer for the group of skippers who have that boat or that manufacturer's boat.

On my manufacturer's boat, the fuse I mentioned earlier is a recurring culprit.

If your boat or your manufacturer's boat has an active owners association, in addition to this fine and helpful website/forum, you could find gems of information like this:

Critical Upgrades http://c34.org/bbs/index.php/topic,5078.0.html

Good luck.

Ken13559 · Apr 21, 2016

I think you only need to fix 1 wire. The one that goes to the starter solenoid.

Sailor_Jeff · Apr 22, 2016

Hi Roy,

When you push the switch to start, and the engine does not start, do you hear a "click" on the engine as nothing happens? If so, it's probably not the switch, wire, or connections, it's most likely the solonoid itself on the starter. This is a relatively easy fix that is not all that expensive.

jeff

RoyS · Apr 22, 2016

Hello Jeff,
Yes, I hear the click and I have already replaced the solenoid. Sometimes I have to push the start button repeatedly until it actually turns over. Starting battery is good and isolated and reserved for starting only. Battery cables on starting battery are large automotive type with standard lead battery post clamp connectors. No. 10 wires are next to be installed in start circuit to the solenoid. The problem is intermittent so I will not be confident in the repair until I have started the motor a few dozen times. Failure, on the other hand, will announce itself clearly enough. Time will tell.

kloudie1 · Apr 22, 2016

Much discussion about this exact problem on the forum. Here is an electrical diagram from Yanmar. The problem is almost always in the connectors at the ends of the extension marked on the diagram. I ran a red fused 10 ga from B on the solenoid direct to the key switch and a 10 ga white from the pushbutton back to S on the solenoid. essentially jumpering and paralleling the existing wires. Label them plainly so that if someone is troubleshooting, they know what they are dealing with. The Tacho sender wires go through the same crappy connectors, so usually that is the source of an intermittent tach.

pateco · Apr 22, 2016

kloudie1 said:
Much discussion about this exact problem on the forum. Here is an electrical diagram from Yanmar. The problem is almost always in the connectors at the ends of the extension marked on the diagram. I ran a red fused 10 ga from B on the solenoid direct to the key switch and a 10 ga white from the pushbutton back to S on the solenoid. essentially jumpering and paralleling the existing wires. Label them plainly so that if someone is troubleshooting, they know what they are dealing with. The Tacho sender wires go through the same crappy connectors, so usually that is the source of an intermittent tach.

Where in that drawing would you add the additional relay. I am pretty sure I know, but just asking.

kloudie1 · Apr 22, 2016

The normally open relay "power connections" go from S to B. The relay coil is connected to the white pushbutton wire and the other relay coil terminal to ground (earth). The white to the solenoid is removed from the solenoid and connected to the coil of the relay. That way the pushbutton activates the coil, closing the contacts connecting the S and B and making the solenoid work 'cause the circuit has almost no voltage drop.

kloudie1 · Apr 22, 2016

Here is a picture posted by one of the forum guys.. Claude Auger, I think

Stu Jackson · Apr 22, 2016

IH82BL8 said:
The question I have is, wouldn't it make just as much sense to simply cut out the two connectors and solder and heat shrink the wires together? Or could the problem be the result of corrosion in the wiring itself, which necessitates replacing the entire harness? For that matter, if the harness runs between the control panel and the engine, why not make a new harness with only teminal connections and no interim connectors? If I did that, is there any reason to or not to slightly increase the gauge of each of the wires?

Those are, of course, the options, and one of the posts in the Critical Upgrades I linked to discusses just that. http://c34.org/bbs/index.php/topic,5078.msg44056.html#msg44056 Your boat, your choice.

RoyS said:
The problem is intermittent so I will not be confident in the repair until I have started the motor a few dozen times.

Anytime something electrical is intermittent, it is 99% of the time the connection. Just like we suggested.

Unless it is a hardware (starter or solenoid in this case), but rarely in all our experience on this and other fine boating forums.

Kloudie's posts #13 & #16 explain the solenoid solution used by Yanmar owners, quite perfectly. [Yanmar wiring harness solution]

Good luck.

kloudie1 · Apr 22, 2016

That is what I did, I ran a continuous wire to-from.. Power to the panel and the white from the pushbutton back to the starter. Works fine.. In the past 25 years of owning this boat, I had cleaned the connectors several times and each time the switch would work for a year or so then revert to intermittent. I always knew if I pushed the button a few times it would eventually work.. didn't bother me much until I had time to run new wire.
I do carry a start button bypass but that is for bleeding and valve setting.

Stu Jackson · Apr 22, 2016

IH82BL8 said:
So...I started the engine again Tuesday evening. It fired instantly, however, I saw the tach jump back and forth between idle and zero a couple of times. I'm thinking this is a symptom of breakdown in the same wiring harness.

- time.

One of the "links within the link" of my previous links was this one, which discussed just this whipping tach phenomenon.

http://c34.org/bbs/index.php/topic,5078.msg44056.html#msg44056

Please, please, please, read the links we provide. We do that to save a LOT of retyping. Thanks.

pateco · Apr 22, 2016

Stu Jackson said:
- time.
http://c34.org/bbs/index.php/topic,5078.msg44056.html#msg44056
Please, please, please, read the links we provide. We do that to save a LOT of retyping. Thanks.

Stu,
Neither of your links work for me. They say "Page cannot be displayed."

Replacing engine starter switch on a H31

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