Likely in need of 28amp Alt - any available?

Hi,

Well I've come to the conclusion it must be my alternator after a long diagnosis that was at best confusing.

Now I have time to deal with the issue again and hopefully get back on the road.

I'd like to just replace with another 28amp, but would like to locate a 28amp first so surgery goes quick.

If anyone has a 28amp they don't have need for, please let me know and your price.

Also assuming the stator failed (TBD) is it worth having it rewound or even possible, and any recomendations of where?

Thanks,

Paul

Be sure it is not the VRR before you go ripping into the alternator. Do you have a lot of electrical farkles on the bike , which would be a more likely clue that it is a shot stator? The 28 amper can survive very well, for a very long time, if the demand put on it is not much more than a stock bike, although the VRR can go out. Replaced mine after 15 years having a bad diode.

Oldschool1 said:

Well I've come to the conclusion it must be my alternator after a long diagnosis that was at best confusing.

Click to expand...

I'd first ask to substantiate that diagnosis before pronouncing it... ;-)

Quite often faulty VRR or corroded/cooked wiring/connectors are the culprit.
Unless not significantly overloaded over longer periods, the hermetically sealed 28A unit proves very reliable...

Oldschool1 said:

Hi,

Well I've come to the conclusion it must be my alternator after a long diagnosis that was at best confusing.

Also assuming the stator failed (TBD) is it worth having it rewound or even possible, and any recomendations of where?
Thanks,
Paul

Click to expand...

Rewinding is a tedious task and something of a lost art and doubt you will find anyone local to do it. Cheaper to replace.

The stator is the outside cover part and can be checked with readings, the rotor is what is driven off engine. There should be no need for guesswork.

Thanks for the replies.

Attached is the link to the previous long endeavor to diagnose and "not guess" though I did not reach conclusion.

If you have some other method i should try - i'm all for it. Something doesn't add up - because all my resistance and ground checks of alt systems show good.

https://www.st-owners.com/forums/showthread.php?132224-Diagnostic-of-28AMP-failure-VRR-check-confusion

Thx,

Paul

Well, have you made tests/voltage measurements with approved wiring and connectors and a new/replacement VRR installed?

The reason why Honda suggests to use their multimeter only, is that some other brands/MFGs might have a too high voltage output, thus damaging the diodes while taking readings...
Rule of thumb: if yours runs on a 9V battery, better don't, if it runs on a 1,5V cell, usage is probably safe... the instructions/specs coming with the multimeter should give full insight...

Thanks for your thoughts I'll take heed of those.

The real mystery is by the checks i just confirmed again below the alt should be producing AC voltage but does not. That is the issue.

The black 2P connector checks out for resistance at 3Ohms and is not shorted to ground. Does this confirm the field coil is ok?

The red 3P yellow alt wires all show about .5 Ohm resistance between any two pairs, and none short to ground. Does this confirm the stator is ok?

I have verified 12 Volts is present at the 2P connector (field coil) for exitation of the field, which is necessary for the alt to produce voltage.

Running i get no AC voltage between any two yellow 3P wires!!!

So this really doesn't add up!

Can anyone add insight to why the Alt would not produce voltage?

Thx,

Paul

ST1100Y said:

Well, have you made tests/voltage measurements with approved wiring and connectors and a new/replacement VRR installed?

The reason why Honda suggests to use their multimeter only, is that some other brands/MFGs might have a too high voltage output, thus damaging the diodes while taking readings...
Rule of thumb: if yours runs on a 9V battery, better don't, if it runs on a 1,5V cell, usage is probably safe... the instructions/specs coming with the multimeter should give full insight...

Click to expand...

New to the ST scene and unless someone else objects this is how I would proceed. The early GW guys when testing stator output remove 3 wire connector and test directly at yellow wires for AC voltage among the 3 pairs, A to B, A to C and B to C. Output of GW stator is higher and would not expect identical readings but look for consistency in the ST output.

Before that though check that you are indeed getting battery voltage at BL wire of field on 2 wire and at VRR. From the '92 manual.

YMMV

http://www.goldwingfacts.com/forums/2-goldwing-technical-forum/307585-i-actually-found-stator-testing-method.html

Paul, I do have a 28 A alternator, I might have VRR as well. Do you wanna try VRR (I'd have to look for it) first or you're sure about alternator? Let me know.

Mark

Oldschool1 said:

The black 2P connector checks out for resistance at 3Ohms and is not shorted to ground. Does this confirm the field coil is ok?

Click to expand...

looking good...

The red 3P yellow alt wires all show about .5 Ohm resistance between any two pairs, and none short to ground. Does this confirm the stator is ok?

Click to expand...

looking good as well...

I have verified 12 Volts is present at the 2P connector (field coil) for exitation of the field, which is necessary for the alt to produce voltage.

Click to expand...

actually 'reducing/limiting' the stator output, but again OK...

Running i get no AC voltage between any two yellow 3P wires!!!

Click to expand...

Odd... sure you'd swapped the leads on your meter to the AC sockets and set the dial accordingly? (no offence intended, just to ensure...)

Technically of course possible that the windings are mechanically broken, engine vibes might cause that area to open...
Other theory would run by an exhausted permanent magnet on the rotor...


Had the 26A alternator of my '94 ST failing on the way to the MOT, like 100m before their w/shop the bike died, zero power, dash just dark, etc...
The bugger had decided to short to ground right there... disconnected the stator and had battery power back... ran fine for the MOT and carried me back home safe...

No offense taken I'm looking for the "senior moment" and would be happy to find it. So appreciate your thinking here

My DVM (a cheap $20 Craftsman) doesn't switch leads for AC, just a dial switch. In AC mode it will read 120VAC at the wall outlet- just confirmed again, actually it does read 0.5 VAC when i test the stator leads (but esentially zero relative to the 50 or 80 expected) . Im reaching for an "ahaaa" moment - is it possible a cheap meter would only read 60Hz in AC mode - thinking this AC is certainly not 60Hz.

Is it remotely possible the alt rotar is not spinning? is the rotor splined to the gear set that drives the shaft. Has anyone ever heard of such a failure?

I'm really at a loss here!!!!!!

Thx - please mention the obvious and not so obvious.

Paul

If you have an automotive friend you trust, or better yet a biker friend that does his (or her) own work, get another set of eyes on your wiring connections. I have attempted to follow the various threads on your charging problem and I'm personally not convinced changing your alternator will fix your problem. The two things your testing with a meter will not tell you:
If you have a low resistance connection with the meter, it can be one strand of a dozen that show those results, but will not pass enough electrons other than to indicate on the meter. VOLTAGE DROP
The meter is measuring many turns of wire designed to develop a magnetic field, so a low reading is "good" but cannot tell you about the magnetic field. AMPERE TURNS
If I were there, I'd be looking for defective electrical connections that won't show with a meter. Like a 12 automotive test light, some medium duty wires to jumper around suspected connections.....you need another set of eyes that understands the electrical portion. Your measurements, (if I followed all of it correctly) indicates that you should have a charging alternator...but you don't.
Yes, there's the possibility it may not be turning, but only having been a member here for about 4 years and having the smaller alternator as you do, I don't recall having ever seen a posting for one that didn't turn.
I'm guessing, it's in the manner of your testing that would be allowing you to miss something that could be narrowed down by some more unconventional methods.
Most people on here have had that "loose battery connection" sometime in your life that allows the courtesy light to go on in a vehicle, but won't crank the starter. That's the closest analogy I can pass along, but there are many more connections here and more difficult to follow with Honda's wiring diagram.
Moral support at this distance only, but I'd get an "experienced spark chaser's" eyes and brain in with you. If it were me, I'd be jumpering power and ground leads with wire, a 12 volt test light and powering that rotor from the battery just long enough to see if it charges (two seconds or less).
Please re-inspect your wire connecting points for any metal that isn't clean, shiny, and looking like new and pull lightly on wire connecting points as it may show a breaking of all but one or two strands of wire that would still test as good. Any wire insulation that appears melted is also suspect.

AC volts will register regardless of Hz. Hz is just a factor of generator speed, 3600RPM would be 60Hz for your typical 2 pole generator.

Just for kicks try it on the DC scale using the appropriate range for a yellow pair and then go 1 yellow to ground. The worst I think can happen would be OL or OR on meter scale as it is showing no AC now.

Doodaa said:

Your measurements, (if I followed all of it correctly) indicates that you should have a charging alternator...but you don't.

Click to expand...

Which is my opinion as well... we're simply overlooking something here... but since we don't sit in front of the rig, we've a hard time figuring out what...

I second the suggestion to get a second pair of (knowing) eyes on site... will probably circle down the source of trouble on no time...

And I don't believe in "senior moments" ;-)
But one gets "routine-blinded" or tend to suffer "tunnel-vision" when staring onto a problem for too long...

In the meantime while looking for a "new set of eyes" i'll try one more thing.

As suggested above, I want to provide voltage to the field coil apart from the VRR source. Theory is - perhaps a static voltage of 11 to 12V at 2P connector is possible but the VRR may not have abiltiy to provide any current to the coil (compromised circuit) to the field is not created.

What is a safe way to provide voltage/current to the field coil to test max output of the alternator. Any ideas on how to apply (12V battery source) or a voltage supply that can limit current by increasing voltage and measuring current. I may be able to borrow a current/voltage limiting supply?

I dont think we really know how this circuit is expected to work (2P excitation voltage), is 12V+- present all the time when 2P is disconnected, but when connected current supply under load is analogly varied to regulate alternator output?

Thx,

Paul (not giving up!)

Oldschool1 said:

I dont think we really know how this circuit is expected to work (2P excitation voltage), is 12V+- present all the time when 2P is disconnected, but when connected current supply under load is analogly varied to regulate alternator output?

Click to expand...

Paul,
the excitation voltage is "varied" by the regulator, to the armature or rotor when working properly, which varies the current (think magnetic field) to produce lower or higher voltage on the stator (yellow) leads. When that 2P connector is connected and the motor running, you should get something of a less than 12 volt reading on those connected black and white wires. IF you measure 12 volts from black to ground AND the same on the white wire to ground, well that's part of the problem.
I use the automotive light tester to do a variety of things, and I'd use it as a current limited (BULB DOES THIS) jumper lead to provide power or ground for testing. I would run the motor with everything connected and test the 2P black and white wires with the test light clipped to the negative (ground) and see if the wires showed the same amount of brightness on both terminals (while connected) and if it charges when you connect to the white wire. (I sometimes use a mirror if my arms aren't long enough)

But, before you try all of this, when you said you measured 3 ohms to the black and white wires.....you were describing the wires going into the alternator, weren't you ?? If not, check that first. It could be just worn off/down brush/slip ring connections. (The electrical connections from the stationary parts to the rotating parts)

We'll get it Yes, you could use a separate power supply to test it, but I'd rather fly out there sooner than explaining it online....used to go rafting East of you

P.S. a "senior moment" in my book is when you just smile at a pretty female and NOT pant or drool.

Doodaa said:

It could be just worn off/down brush/slip ring connections.

Click to expand...

The 26A unit is a "brush-less" design ;-)
Which is why it has the "4th winding" fed by the VRR to suppress the field of the mains-windings when the (secondary) output climbs over ~14,7VDC...
So methinks if you apply anything up 12VDC onto those leads, the mains field might 'collapse', thus nil output there... or vice versa, means it needs ~12VDC on white/black to actually "excite" the field...
Unfortunately is the w/shop manual blank on those numbers and I'd never taken live measures on a running system either...

But since the stator windings show proper resistance/conductance and as long as the rest of the wiring harness also proves OK, my money would be on a fried VRR...
Check the white connector shell at its base, the crimps inside as well as the spades and the resin on the bottom of the VRR for signs of overheating/melting...
Same on the red 3-pin connector shell & crimps for the stator winding, when overload and/or humidity caused corrosion happens, those connections are prone to suffer...

Hint when installing a VRR: apply some heatsink paste (the white stuff known from CPU coolers does fine) where its aluminium backside contacts the cast of the footrest plate.

ST1100Y said:

The 26A unit is a "brush-less" design ;-)
Which is why it has the "4th winding" fed by the VRR to suppress the field of the mains-windings when the (secondary) output climbs over ~14,7VDC...
So methinks if you apply anything up 12VDC onto those leads, the mains field might 'collapse', thus nil output there... or vice versa, means it needs ~12VDC on white/black to actually "excite" the field...
Unfortunately is the w/shop manual blank on those numbers and I'd never taken live measures on a running system either...

Click to expand...

Thanks for that info, I was unaware of that twist to the type of system and great to know before having to get my hands dirty. A great idea to eliminate moving parts, increasing reliability :

Doodaa said:

A great idea to eliminate moving parts, increasing reliability :

Click to expand...

That actually was the intention by Honda when going with this design, until 'someone' came to the bright idea of running PIAAs and heated panties on that electrical system... ;-)
So now the air-cooled 40A unit, more juice but prone being attacked by liquids... in the UK the stator steel rusting cracks the casings into bits (one actually seized up the engine), and if you've an unseen coolant leak, seeping over the aft of the engine, the chances are quite good that the antifreeze eats away brushes, collector and the internal VRR...

ST1100Y said:

The 26A unit is a "brush-less" design ;-)
Which is why it has the "4th winding" fed by the VRR to suppress the field of the mains-windings when the (secondary) output climbs over ~14,7VDC...
So methinks if you apply anything up 12VDC onto those leads, the mains field might 'collapse', thus nil output there... or vice versa, means it needs ~12VDC on white/black to actually "excite" the field...

Click to expand...

Am I understanding this right; 12 V at the field (2P connector) should provide max output of the stator, or 0V on the 2P provides max output of the stator?

My understanding was the 12V sets up the magnetic field which is necessary for the stator to provide output - therefore 12V should provide max output. If this is not the case this would be a new design concept understanding for myself.

Also to confirm, the 3 Ohm resistance is on the Alternator side of the 2P connector (black and white wires).

Thx,

Paul