Can Yanmar Starter Solenoid be Repaired?

[ebisucapt]

The contacts in side the solenoid on my 3GM are not always making contact. Most likely just need some cleaning. But is there anyway to take it apart? Looks sealed to me. Anyone know different?

[Bill Seal]

The copper contact disc is probably pitted and shot. Find what Toyota starter uses the same solenoid and buy a new one at an auto parts store.
I have taken one apart and flipped the disc over, but that was on a Jeep in the middle of nowhere.

[Lepke]

I generally fix the solenoid when it fails. The solenoid may either screw or rivet together. If it's riveted, it's a little more work to drill out the rivets and later re-revit. I usually file the disk until it's smooth. With a good, sharp file it takes a minute. Also file the studs that contact it. The solenoid will work about as long as it did new.

But with all the cheap Chinese auto parts, it may not be worth your time.

[Jon Hacking]

Originally Posted by ebisucapt

The contacts in side the solenoid on my 3GM are not always making contact. Most likely just need some cleaning. But is there anyway to take it apart? Looks sealed to me. Anyone know different?

This is actually a common problem, especially for cats. What makes you think it's the solenoid that's at fault?

Short between the big positive terminal on the solenoid & the solenoid trigger connection (the wire coming down from the key-switch). You can do it with a screwdriver or a short, stiff piece of wire.

Does it start? If not, then you're probably correct, & you should replace the unit. On our 4JH2E, the starter & solenoid are a single unit, & the solenoid also throws out the Bendix gear to engage the teeth on the flywheel. You can get after-market parts that look just like the original, usually for much cheaper, at any good starter/alternator repair shop. We've been using one (bought in Langkawi, Malaysia) for years with no problems.

But if your engine DOES start by jumping it, the problem is probably low voltage to your solenoid, mostly caused by corrosion in your wiring, but also by poor design. Yanmar, in their infinite wisdom, has a relatively small positive feed wire to the control panel, & they then run all of the current for the solenoid through the key-switch, from which it has to get back down to the engine (a long way on our cat). The accumulated voltage drops are the usual starting problem.

Clean up whatever connections you can find, but the best solution is to buy a little 12v relay from any car-parts shop. These are about a 1"/25mm cube, with 5 spade connectors coming out the bottom. They cost under $10 & the contacts can usually handle 40A (which is gross overkill, but OK).

Wire it down by the starter. The start wire from the key-switch goes to the coil on the relay, with the other coil connection going to any convenient ground. Run a wire from the positive lead on the solenoid to the Common on the relay, & the Normally Open connection goes to the solenoid trigger (where the key-switch used to connect to). The Normally Closed connection is unused.

Now, turning your key to Start will activate the relay, which will in turn activate your solenoid, but the difference is that the solenoid will now get the full 12v, so should throw much more forcefully.

Good luck!

[wsmurdoch]

Are you sure it is the solenoid? 3GM/HM engines have a history of wiring harness related starter problems. For instance... https://www.cruisersforum.com/forums...tent-9085.html which was the first thread that a search turned up.

[jim King]

Could be an undersized cable not allowing enough juice to flow from the batteries to the starter. Had a similar problem and a friend with a good flow meter tested it. We put on a thicker cable and the problem was solved.

[ebisucapt]

So this is on a cat. On the closer side to the helm. (Starboard side) the port side does have the relay mentioned by Jon Hacking. Both engines have same cables and both worked fine till a few months ago. I don’t think it is wires as it clicks and can feel it move each time the key is turned. It usually starts the third time. But I know one of these days it will not be the case and will happen in heavy winds being pushed into a lee shore. Or some other emergency. It doesn’t do it every time just most times. But Jon I will try jumping it and see if it happens.

.

[Dockhead]

Originally Posted by Jon Hacking

This is actually a common problem, especially for cats. What makes you think it's the solenoid that's at fault?

Short between the big positive terminal on the solenoid & the solenoid trigger connection (the wire coming down from the key-switch). You can do it with a screwdriver or a short, stiff piece of wire.

Does it start? If not, then you're probably correct, & you should replace the unit. On our 4JH2E, the starter & solenoid are a single unit, & the solenoid also throws out the Bendix gear to engage the teeth on the flywheel. You can get after-market parts that look just like the original, usually for much cheaper, at any good starter/alternator repair shop. We've been using one (bought in Langkawi, Malaysia) for years with no problems.

But if your engine DOES start by jumping it, the problem is probably low voltage to your solenoid, mostly caused by corrosion in your wiring, but also by poor design. Yanmar, in their infinite wisdom, has a relatively small positive feed wire to the control panel, & they then run all of the current for the solenoid through the key-switch, from which it has to get back down to the engine (a long way on our cat). The accumulated voltage drops are the usual starting problem.

Clean up whatever connections you can find, but the best solution is to buy a little 12v relay from any car-parts shop. These are about a 1"/25mm cube, with 5 spade connectors coming out the bottom. They cost under $10 & the contacts can usually handle 40A (which is gross overkill, but OK).

Wire it down by the starter. The start wire from the key-switch goes to the coil on the relay, with the other coil connection going to any convenient ground. Run a wire from the positive lead on the solenoid to the Common on the relay, & the Normally Open connection goes to the solenoid trigger (where the key-switch used to connect to). The Normally Closed connection is unused.

Now, turning your key to Start will activate the relay, which will in turn activate your solenoid, but the difference is that the solenoid will now get the full 12v, so should throw much more forcefully.

Good luck!

This.


Low voltage to the solenoid is a known issue with many Yanmars, something I went through myself with a 4JH3HTE.


Commonly solved by powering the solenoid via a relay with a thick wire from the positive terminal on the starter itself.

[Cheechako]

Originally Posted by ebisucapt

So this is on a cat. On the closer side to the helm. (Starboard side) the port side does have the relay mentioned by Jon Hacking. Both engines have same cables and both worked fine till a few months ago. I don’t think it is wires as it clicks and can feel it move each time the key is turned. It usually starts the third time. But I know one of these days it will not be the case and will happen in heavy winds being pushed into a lee shore. Or some other emergency. It doesn’t do it every time just most times. But Jon I will try jumping it and see if it happens.

.

Clean the wire ends. Sometimes they look good but have wet corrosion on the contact surfaces held by a nut.

[sailcrazy]

following.

[Davo1404]

Yes have had the clicking noise when trying to start my 2gm20f. Went through all the wiring, even found the hidden fuse. As others have said it is voltage drop along the undersized wire & connections. Installed a relay close the starter motor & problem solved.

[chasfgr]

As already said, the solenoid seldom fails - usually the problem, with it clicking but not starting the engine is down to poor connections.
Start by checking your starter battery has all cells working and up to charge.
Then clean and grease the terminals.
In 35 years with Yanmar solenoids I'v never yet had to clean one.
Towards the end of their life they do sometimes arc, at which point cleaning the contact MAY work - the most usual failure mode is the the solenoid fails to energise- poor contact.

[Halifax Sailor]

I was in a far out area on holiday weekend. My Honda stopped starting and after taking apart the solenoid I had to re-build/build up the inner contacts with silver solder and file down to fit. Sold the car about 4 years later, never had to do anything else to it.

[EmeraldCoastSailor]

My 2009 Beneteau's 2008 3YM30 Yanmar has a relay on the back of the engine that activates the starter solenoid. Recently, I had what I thought might be a solenoid issue (engine would not turn over). My start batt measured good voltage on the monitor and at the terminals but it was old so I replaced it. I also cleaned the white wire's spade connector on the solenoid that comes from the relay triggered by start switch. All good now. At least I hope I have solved the problem.

[captnknopf]

I have taken solenoids apart and frequently the contacts connected to the bolts are round but only half of the contact is used. Sometimes you can loosen the lower nut (after removing the upper nut holding the big wire) and with both nuts tightened together, rotate the stud half a turn, putting a new section of contact in place. This only works once (like every ten years) before needing to replace the solenoid. An easy fix if it works