YM1110D Won't Charge

[OhioBruce]

My 1110d won't charge. With the engine running I unplugged the alternator (generator?) and used a multimeter to test for voltage and it read zero.

I removed the alternator (generator?) and see that it is a permanent magnet type.

I've done a little research and I'm confused about if it is an alternator, generator, dynamo, and how to test it and the voltage regulator.

If anyone could give me some advice on how to proceed I'd appreciate it.


Thanks,
Bruce

 

[winston1]

I have no idea what is on the 1110. Sorry :confused3: If is is a dynamo you would test touching the two outlet terminals on the dynamo with tester set on ac volts. Should have 13+ ac volts depending on speed.

 

[Roadworthy]

Take the alternator and voltage regulator to an alternator repair shop. They can tell you what you've got and what it should be doing. Parts should be less expensive than a tractor repair shop.

 

[OhioBruce]

Good idea. I removed the voltage regulator tonight and will take them both to the repair shop this week. Thanks!

 

[rScotty]

My 1110d won't charge. With the engine running I unplugged the alternator (generator?) and used a multimeter to test for voltage and it read zero.

I removed the alternator (generator?) and see that it is a permanent magnet type.

I've done a little research and I'm confused about if it is an alternator, generator, dynamo, and how to test it and the voltage regulator.

If anyone could give me some advice on how to proceed I'd appreciate it.


Thanks,
Bruce

I can help you with it if you would prefer to learn about them or do it yourself. Certainly there isn't anything wrong with just taking it to an automotive electrical shop. But sometimes it is fun to know a bit more. And you did ask some good questions.

BTW, the most common problem with an alternator, AC generator, or magneto (all sort of the same thing) is not the magnets or the coils inside, it is usually that the diodes on the diode plate on the back of the AC generator have failed. You might try your multimeter on the AC setting and see if spinning the alternator on the tractor gives you about 20 volts AC instead of any DC voltage. If so, it's one or more diodes that need replacement. They just solder in.

I'll answer some of your questions for the future

Is it an alternator or a generator or a dynamo? Well, it's any and all of those. They all do the same thing. Anything that generates electricity by moving a magnet a past a coil is a generator of some kind. And more specifically, it is an AC generator. No matter how, all generators make AC voltage by moving a magnet by a coil, and each one has a different way to convert that AC voltage into a DC voltage that is more easily regulated and can be used to charge a lead/acid battery. The different names actually refer to how each one converts the AC voltage into a DC voltage.

The traditional automotive GENERATOR from about 1920 up till the mid 1960's used carbon brushes running on a divided plate called a "commutator" to mechanically convert the AC it made into a DC that could be regulated and used for batterys and lights. Magnets at the time were weak, so instead of magnets, the GENERATORS used large "field coils" to make a magnetic field that their other coils moved past. GENERATORS were big and heavy and complicated....but remarkably reliable.

Later on, in the mid 1960s, two things happened: Semiconducting diodes were invented and could be used to convert AC into DC. These diodes did away with the need for brushes and commutators.
At about the same time, the first of the modern high powered synthetic magnets "ALNICO" was invented. ALNICO magnets did away with the need for field coils.
As a result, the ALTERNATOR was born.

Note that you still have to have a motor to move the coils & magnets past one another, and there are some times when the motor is built right into the GENERATOR or ALTERNATOR. When that happens, the combination is called a DYNAMO.
Household backup generators and portable welding generators are examples of DYNAMOs in use today. Just to confuse things, they are both called generators instead of their proper name which is a dynamo. And to confuse things farther, they are more closely related to motors plus alternators than they are to the ancient motors plus generators of the early 1900s....But if you put a motor and a generator together you have a DYNAMO.

The whole basis of all of this is the simple fact that anytime you move a magnet past a coil or a coil past a magnet you generate a voltage in the coil. The voltage goes up - call it positive - as the coil approaches the magnet and the voltage goes in the other direction - negative or down - as the coil moves past the magnet and away. Voltages that goes up and down between positive and negative that way are called alternating currents. The voltage goes up the faster the magnet and coil move past each other.

Yes, you can move the magnet past the coil if you had rather. And in your Yanmar's AC generator that is how it is done. Usually its a set of six magnets and six coils. Six of each (the number doesn't matter) just to smooth things out. And by moving the magnets and letting the coils stay stationary, you don't have a problem with how to keep the output wires from winding up. If the coils are stationary and the magnets are moving, the wires from those coils are also stationary and that turns out to be a big advantage. If you end up designing it the other way around so that the coils move and the magnets are stationary then you have to interrupt the leads from the coils by connecting them to brushes contacting a rotating ring.... ugh. Better to just move the magnets.

There is probably no need to take your Yanmar alternator apart. All you would see inside is a group of coils all bolted to the backing plate and connected in series, and some magnets cast into the rotor so cleverly you probably cannot even see them. Neither one is likely to go wrong. If you can get to the leads coming from the coils and measure the output there without them being connected to the diodes then you will probably see about 20 volts AC.

If you measure it after the diodes are involved it will be about 12 to 15 volts DC depending on RPM.

You can test the diodes with your multimeter using the ohm (continuity) setting, but you have to disconnect them from the circuit to do so. One side of the diode is screwed to the backing plate, and the other has a wire soldered to it. Unsolder the wire - carefully & quickly because diodes are a little bit sensitive to heat - and the diode should show continuity measured between the free end of the diode and the base plate with the test leads in one polarity. And it should show no continuity with the test leads reversed. Anything else means replace that diode.

If the AC generator (alternator) doesn't show DC output when it is spun, chances are good that bad diodes are the problem. Especially so if it does show AC output....

If the multimeter does show output from the alternator, then the problem is in either the voltage regultor. the ignition switch, or the battery itself. We can go as deep into those as you would like, but this is a good place to quit for now and see if anyone has a question.

enjoy,
rScotty

 

[OhioBruce]

rScotty - Thanks for all of that info! I do like to learn and do everything myself if at all possible. I'll take a look and see if I can find the diodes and test them with my multimeter.

Thanks!
Bruce

 

[OhioBruce]

Well, I didn't see anything that was easily desoldered so i just took it to the alternator shop. They tested it and told me it was shot and they could not repair it. They could not test the voltage regulator.

I took it to a second shop and they told me that they were swamped with work and couldn't test it, but if it was bad, they couldn't repair it anyway. They also told me that they couldn't test the voltage regulator and I should try replacing it first to see if that was the problem.

Here is a pic of the alternator. Are those cylindrical things with the wires soldered the diodes?

 

[rScotty]

Yes they are the diodes.

BTW, you can test it for yourself if you want....it's only a 50% test, but will tell something.
1. Look at the front of the engine and figure out which way the alternator should spin.
2. bolt the pulley or something similar to the front of the alternator.
3. Hook up your multimeter leads to those two wire coming out from the coils - these are the black and white? wires at the top of the picture. Set the multimeter to 50 or 100 volts AC.
4. spin the alternator. The easy way is to just hold it up against a rotating wire brush. You might have that in the shop or have one you can chuck into a drill...or whatever.
See what you get.

We can test the diodes. The coils can be thought of as a short circuit. In fact you should test for continuity between the two coil wires before you do the test above. There should be continuity between the upper two connections where you measure the AC voltage. Continuity and AC voltage when it is spun tells you the coils are good. If so, we are going to win....well, we win anyway, because we can always re-wind the coils...but it's a pain.

If the coils are putting out, we then get into how to test the diodes. BTW, this is the simplest circuit ever. We may just leave them there and buy (or make) a simple diode plate that is mounted outboard of the alternator.
rScotty

BTW, I don't think much of your electrical shop guys.

 

[OhioBruce]

Yes, I didn't think much of those guys either. I didn't believe it couldn't be fixed so I stopped at the second shop - and he was worse.

Anyway, I stripped some insulation off the wires and connected test leads like this:





1. I have continuity.
2. When I spun the alternator by hand I got 5 volts. I pressed it against the wire brush on my bench grinder and it quickly went up 15 volts and I stopped when it hit 20 volts as it gained speed.

I looked carefully at the diodes and can see evidence of a previous repair and one solder joint looks marginal. I like the idea of making a separate external diode plate. I've built speakers so I have some rudimentary fabrication/electronic/soldering skills. Mostly I can follow directions. Lol.

I really, really appreciate your help!
Bruce

 

[rScotty]

That's great! Typical alternator....good coils; probably a bad diode.
We could have wound the coils if we needed to, but nice not to have to.

A diode is a one way valve for electricity. To test a diode, it is necessary to disconnect any diode from the rest of the circuit. Then you can test the diode with your continuity checker. Place one lead on the obvious diode terminal and the other lead to either the other diode terminal - or if it doesn't have but one obvious terminal the other terminal is the diode case itself which is being used as a common case or body ground. A diode will always have two "terminals", although one "terminal" may be the diode case itself

A good diode will show continuity (zero the meter & record the ohms) with the leads connected to the two terminals of the diode one way, and then when you reverse the leads it will show no continuity. That is all there is to the test. The diode acts this way because the diode is being a one way valve relative to the polarity of the battery that is in the multimeter.

If you make chart or some sort of list of your measurements on each diode that will help us both.

All 4 diodes are supposed to be electrically the same. Sometimes they are physically the same, but not always. Looking at that alternator picture, I wonder you took out those two phillips screws and looked beneath you would see that all 4 diodes are the same except that two of the four are mounted upside down? It would make sense go take those phillips screws out and check that.
If you do so, make up a sketch of how the wires under the plate are connected.

If we do decide to make up a diode plate, we will use any regular automotive diodes and wire them so that polarity-wise so that we can rectify both sides of the AC wave that they are seeing. That means that electrically speaking, you have two diodes connected one way and two the other way around. But we can get into that after we know the status of the diodes you have.

Yes, either way we do it testing diodes does require either unsoldering the wires to the diodes or somehow isolating each one to test it individually. We don't have to remove them from the diode plate, but at least one of the diode terminals that has the wire going to it has to be disconnected. One way to avoid unsoldering is to clip the wires between the diodes at the midpoint. That way we can then butt joint them with a short jumper later. That avoid heating the diodes up directly but is sort of a cludge fix. If you are confident with your soldering skills just unsolder the wire.
The diodes are sensitive to heat, but they aren't terribly so. After all, look where they live.

glad you are doing this, it's fun even if we do end up getting a rebuilt alt. from somewhere.
rScotty

 

[rScotty]

I got up this morning and re-read what I had written as reply #10. It was kinda confusing so I saw I could edit it and just did so.
It's a lot better now.
My apologies to anyone trying to make sense of the original. That will teach me to try to type up something while doing something else at the same time.
rScotty.

 

[OhioBruce]

After dropping it and breaking off a chunk when trying to bend it back, I cleaned off some grime and desoldered it. Then I labeled each diode like this:



Here is what it looks like under the plates:




Then I took the following readings:

Diode 1 - Negative on the plate, positive on the diode wire = .605 ohms. Positive on the plate and negative on the diode wire = no continuity.
Diode 2 - Negative on the plate, positive on the diode wire = .560 ohms. Positive on the plate and negative on the diode wire = no continuity.
Diode 3 - Positive on the plate, negative on the diode wire = .613 ohms. Negative on the plate and positive on the diode wire = no continuity.
Diode 4 - Positive on the plate, negative on the diode wire = .611 ohms. Negative on the plate and positive on the diode wire = no continuity.

I also verified there was continuity between each diode housing and the mounting plates.


Diode 2 is off from the others, but doesn't seem to be that big of a difference? So, maybe it is the voltage regulator?

 

[CoyPatton]

After dropping it and breaking off a chunk when trying to bend it back, I cleaned off some grime and desoldered it. Then I labeled each diode like this:



Here is what it looks like under the plates:




Then I took the following readings:

Diode 1 - Negative on the plate, positive on the diode wire = .605 ohms. Positive on the plate and negative on the diode wire = no continuity.
Diode 2 - Negative on the plate, positive on the diode wire = .560 ohms. Positive on the plate and negative on the diode wire = no continuity.
Diode 3 - Positive on the plate, negative on the diode wire = .613 ohms. Negative on the plate and positive on the diode wire = no continuity.
Diode 4 - Positive on the plate, negative on the diode wire = .611 ohms. Negative on the plate and positive on the diode wire = no continuity.

I also verified there was continuity between each diode housing and the mounting plates.


Diode 2 is off from the others, but doesn't seem to be that big of a difference? So, maybe it is the voltage regulator?

Any time checking continuity, I prefer clean contact points. Meaning you would probably get slightly less resistance if the plate were clean at least where you placed the lead.
But regardless your readings are correct for 1 way diodes.
Also I have no ideal how the diode is mounted to the plate so some of the resistance could be from this as well.

I have no ideal on where the resistance should ohm at for those diodes, but issues with the regulator mounted on the firewall would not surprise me at all.

 

[rScotty]

Congratulations! You just tested all the diodes and they came out good. The one that tested differently is suspect, but it's within 10%, so I'm going to call it good. In fact, it is looking like your alternator is good. Time to clean and reassemble. Then of course we wil then test it one more time before going on to the voltage regulator.

Going back to message #9, I assume that with the alligator leads clipped on like you show, that the readings you got were AC voltages.. true? And that told us the internal alternator coils and magnets are good. Now that we don't have the diodes in the circuit might as well now double check that neither of the coil wires has continuity to the case.

The photo in message #9 also shows the output wires from the alternator - looks like a yellow wire and a red wire with the red wire in a black sleeve.... Hmm... I wonder why the red wire is sleeved? I can't quite see where it comes from, but isn't it coming from a tab under the phillips screw? That would mean it was common frame ground so why sleeve it? It's the other one - the yellow wire - that I would expect to be sleeved.
Hmm....looking closer, why is there a butt connector on the red wire? Has someone been there before?
Hey! is that abrasion that I see on the yellow wire? Hard to make it out, but is there any chance that wire insulation is worn away and the yellow wire touching some part of the motor or frame? Surely not...although that would explain all.

So if the yellow wire isn't abraded and touching, solder all back up and then test the AC output like you did before. No point to go up to 20 volts. Just check that it is the about the same. And then hook your multimeter to the other end of those yellow and red output wires. This time when you rotate the alternator you will get about 3/4 of the voltage but it will be DC. Or at least it should be DC if the rectifier diodes are doing their job. Actually, what you will get is a pulsating DC, so depending on the sophistication of the multimeter and how fast you spin it the meter may try to tell you it is still looking at AC. Anyway, see what you get.

If you get about 3/4 of the voltage from the red and yellow wires and it is DC when spun fairly fast, then we have a good alternator and it can be put back onto the motor. The next step is the voltage regulator, but depending on how yours is wired, there is a chance that the ignition switch in involved.

With the alternator back on the engine, it is time to check the continuity on the ignition switch first, and then see what kind of voltage regulator that it has. Yanmar used several different VRs. And although we can fix them all, it is rarely worth the effort.

We check the ignition switch first because sometimes the alternator output runs through the ignition switch and then to the voltage regulator. You need to trace the wires to find out because Yanmar did it both ways. And because the corrosion on the back side of the alternator plates make us suspicious that the inside of the ignition switch may be similar. The switch can be taken apart and the contacts cleaned, but it is picky work and there are little springs in there that rust, too.....not to discourage you from trying.

And the voltage regulator is encapsolated in epoxy.
In fact, we may end up just ordering one or both from Hoye.

But first lets make sure the alternator is good. Put it back together, check for abrasion of the yellow wire, and give the AC & DC spin tests. If good, back on the engine it goes.
luck,
rScotty



The

 

[OhioBruce]

Coy - I filed a small spot on the plates and tops of the diode wires to get a fresh contact point. I think they are pressed in. I can't see any solder.


rScotty -
Message#9 was AC voltage.
Neither coil wire has continuity to the case.
Yellow wire is not abraded.
It does look like it's been worked on before. The phillips screw that holds down the red wire has a buggered head.
Checked AC output with nothing connected to the wires and I'm getting 5 volts just spinning by hand the same as before.

Heading out to put it back together.

 

[rScotty]

Coy - I filed a small spot on the plates and tops of the diode wires to get a fresh contact point. I think they are pressed in. I can't see any solder.


rScotty -
Message#9 was AC voltage.
Neither coil wire has continuity to the case.
Yellow wire is not abraded.
It does look like it's been worked on before. The phillips screw that holds down the red wire has a buggered head.
Checked AC output with nothing connected to the wires and I'm getting 5 volts just spinning by hand the same as before.

Heading out to put it back together.

OK. That's all good. What did you get from the two output wires (yellow & red) when you spun the alternator? Anything?

 

[OhioBruce]

I put everything back together and made sure I had fresh metal at all contact points. I also put some shrink wrap on that yellow wire to be sure it wasn't grounding out.

Set my multimeter to DC and clipped on the alligator leads. Gave it a spin and had about 3 volts. Pushed it against the wire brush and it quickly climbed to 12.7 volts DC. Woo Hoo!

So, given that I tested it with the same multimeter while the tractor was running and got nothing, I'm wondering if it had some corrosion or short somewhere? That screw that held the red wire was barely finger tight when I took it apart.

Now to put it back on the tractor and see what happens. First I need to get a belt - the old one is shot.

Thanks!

 

[rScotty]

I put everything back together and made sure I had fresh metal at all contact points. I also put some shrink wrap on that yellow wire to be sure it wasn't grounding out.

Set my multimeter to DC and clipped on the alligator leads. Gave it a spin and had about 3 volts. Pushed it against the wire brush and it quickly climbed to 12.7 volts DC. Woo Hoo!

So, given that I tested it with the same multimeter while the tractor was running and got nothing, I'm wondering if it had some corrosion or short somewhere? That screw that held the red wire was barely finger tight when I took it apart.

Now to put it back on the tractor and see what happens. First I need to get a belt - the old one is shot.

Thanks!

Maybe we got lucky and all it needed was cleaning. That's not usually the case with alternators, but then they aren't usually that corroded either.
A little bit of electrical current jumping across the micro-space between two dissimilar metals is as good as battery acid for promoting corrosion.

Cleaning was often the answer with old "DC" generators - the kind with brushes and commutators. But there is was usually carbon from the brushes everywhere. There was even a special tool used to clean out the slots in the commutator.

I always figure if I don't know what I'm doing, then cleaning and reassembling can't hurt & I might learn something.
And today as in yesteryear the key to making any carburetted gasoline engine that has set for awhile run right again is to simply take the carb apart, clean all the orfices, needle and seat, ....and reassemble.

We did sort of take the slow, craftsmanlike, step-by-step mechanical method, didn't we?
Good on us so far,
rScotty

 

[OhioBruce]

Yep, I've enjoyed taking this step-by-step and learning a little about alternators. I always fix anything I'm able to and like to put new skills in my toolkit. I appreciate your patient guidance.

You're right about cleaning a carb. I learned the hard way that you can't get by with just cleaning the needle valve and main jet.

I'll get a belt tomorrow, install it, and report back.

Thanks!
Bruce

 

[OhioBruce]

I got a belt, installed everything, cranked it up, and got this:







This was at 3/4 throttle. At idle it puts out 13 volts. Once I throttle up a little it climbs back up to 14 volts.


We did it, rScotty! :thumbsup: :thumbsup: :thumbsup:

Not only did I save a ton of money, I learned something along the way.

Thank you very much for helping me!