Alternator/(generator?) not charging

[Purloined]

2000 V11 Sport.

It is referred to as both in my manual, not sure which it is, but whatever it is, it don't appear to be charging.

Was riding it home the other night and it sputtered, died and the starter would not spin. Charged the battery and it runs as it should.

Put a meter on the battery with the bike at idle, roughly 12.4v, (which is what it reads when it is not running) increased idle and it did not change.  

Put a meter on the two yellow wires that output from the alternator. At idle it registered +/-3.5, 4.5 at about 3000rpm. 

The dashboard alternator indicator does not light (goes out after startup.)

30Amp fuse is intact and seems fine, all the electrical accessories operate (horn, hi/lo, signals etc)

Is this something that can be rebuilt? Replaced?

[docc]

Very common for a yellow output wire to break off at the stator. It is rather hard to see. I replaced my last one with an improved stator from EuroMotoElectric, IIRC. It has improved heat shielding and strain relief.

I should be able to find links to that thread, the supplier, and post images in a few hours . . .

[Weegie]

Certainly doesn't sound very promising, I'm curious about the 3.5-4.5 readings what was that Amps?

Best way to check the Alternator is to disconnect the 2 yellow wires and put a meter on them.

Set the meter for AC Volts range 60 or greater and rev the engine to 3k, you should see 40 Volts AC and 15 Volts AC at 1k or so if it's good.

I prefer to run it up to 3k as you're not flogging the engine to death mechanically unloaded but have the revs high enough to ensure the Alternator should be giving you an output

Of course when you disconnect the the Alternator you're running on battery only so top up the battery on a charger afterwards

[Purloined]

Thank you.  I'll go out and scrutinize it.

The reading on the meter did change slightly when the I increased idle. I don't know if that was an anomalous fluctuation. 

Since I'm an obsessive doom-scroller, my manual calls for removal of the alternator after removing the engine. It sure looks like it would clear; the problem is holding the crankshaft from spinning when loosening, 'special tool 12 9118 01'. Is it possible to do this with the engine in the frame? 

[Purloined]

Yeah, Weegie, I measured the alternator output on the two yellow wires coming off the alternator heading to the regulator.  I pried the connection apart just enough to get the probes in. And I spun it at 3,000 rpm.    I'm sketchy on the electrical nomenclature, but pretty sure we were measuring amps, as that was what we measured at the battery; engine off/engine idle/@ 3,000 rpm.  My friend measured it for me, I'll double check with him on what we measured. 

Hopefully a severed wire as DOCC suggested might be the cause. 

[docc]

So, yes, the stator can be changed in situ. Certainly easier on a lift. 
 

It is common that those wires get strained removing and replacing the alternator cover to turn the motor for valve adjustments. Plus, those wires heat harden where they solder in. The improved stator looks well designed.

[docc]

Here ya go, @Purloined:

 

 

[Weegie]

No clue what a good AC current reading would be, it does sound low though.

Anyway @docc to the rescue

If it was me I'd visually inspect it and check the AC volts as these are pretty easy to do before pulling it apart.

Lot's of luck and I do hope it's not Donald Ducked.

[Purloined]

Yes, Weegie, def volts were measured, not amps as I earlier stated. 

As far as I can tell, the yellow connections on the stator are intact, certainly not obviously detached. 

I spoke with a local shop that rebuilds alternators and took some pix of the unit to show to him, I'm a little confused as to what is possible as regards rebuilding, I think he said he would only need the stator. This will doubtless be contradicted tomorrow and I will be back here tomorrow bellyaching like I do. 

I looked at the ElectroSport stator that docc linked; which is out of stock since the last one they had is now likely residing in Tennessee.  

[docc]

57 minutes ago, Purloined said:

Yes, Weegie, def volts were measured, not amps as I earlier stated. 

As far as I can tell, the yellow connections on the stator are intact, certainly not obviously detached. 

I spoke with a local shop that rebuilds alternators and took some pix of the unit to show to him, I'm a little confused as to what is possible as regards rebuilding, I think he said he would only need the stator. This will doubtless be contradicted tomorrow and I will be back here tomorrow bellyaching like I do. 

I looked at the ElectroSport stator that docc linked; which is out of stock since the last one they had is now likely residing in Tennessee.  

That's too bad (that it is out of stock). This is my third stator and I am suitably impressed with their improvements.

Perhaps if your rebuilders would care to see that image of that heat shielding and improved strain relief and apply their own version . . .

[docc]

This one:

Compared to the vulnerable factory original:

[Purloined]

1 minute ago, docc said:

This one:

I saw that on the link you provided. 

It's oddly beautiful, I'd feel bad burying this object inside the little alternator house.    

I'll print that out and show it to the local guy, sure he's seen a lot of hardware in his day, I'm thinking this one will melt his jaded heart. 

[Weegie]

Last thing from me

If that was AC Volts and not DC Volts then it's definately defective, ideally the test is carried out using a good quality meter. In the thread docc pointed to you can see warnings about cheap meters having problems with AC ranges. If the meter was set on DC Volts I'd expect a small reading as there usually is a small DC component.

EDIT

Thinking about this some more I realized you still had the alternator connected to the Reg/Reg when you took the 3.5-4.5V measurement, if I understood you earlier.

The Voltage test needs to be conducted with the Alternator "Open Circuit" (in other words disconnected from the Reg/Rec), so no idea what voltage to expect measuring that way.

This is from the Centauro manual but I'm pretty sure the V11 runs the same alternator

Alternator
With the engine switched off, disconnect the two yellow generator cables from the rest of the system and then
carry out the following tests with a ohmmeter:
Check the winding isolation towards earth
Connect one connecting point of the ohmmeter to one of the two yellow cables and the other connecting point
to earth (laminar pack).
The instrument should indicate a value above 10 M
Check the winding continuity
Connect the two connecting points of the ohmmeter to the two yellow cables.
The instrument should indicate a value of 0.2÷0.3 .

Good Luck with it, it does sound like it's defective and you're well on the way to getting it repaired

[Purloined]

My apologies for wasting the people's time with my confused understandings. 

As has been suggested, my friend re-tested the output this morning. (he has a decent meter)

DC measured at the battery, with the engine running 12.4v regardless of RPM.

AC measured from the yellow wires off the alternator, upstream from regulator: 16.3v AC at idle drops to 13.2v AC at 3,000 rpm. 

The measurements at the battery might suggest a problem with the rectifier, is that correct? The output from the alternator should not drop as rpms increase, also correct?

I am going to trek to the electrical shop, but I wondered what you guys might construe from this.

[docc]

No apologies necessary! Pretty sure @Weegie (and others) get as much out of these puzzles as I do.

The  V11 Workshop Manual give the following values for alternator output in AC volts:

1000  RPM  15 vAC

3000 RPM  40 vAC

6000 RPM  80 vAC

If your alternator is not functioning, I don't think the regulator can be evaluated solely on the present voltage reading until the alternator is actually putting out.

There are some resistance and diode tests that can be performed on the regulator statically, but seems reasonable to get the alternator around and recheck the running voltages at that point.