Charging problem

[ducpainter]

Sounds expensive...

Check out Rick's and Electrex...

and ebay of course.

[Howie]

Sounds like your stator is bad, but I am a bit confused.  You say when testing voltage to the battery the reading drops to near 0.  If the meter is across the battery terminals or from positive on the battery to ground you should be reading no less than battery voltage.  Maybe try another meter.

As duckpainter said, check resistance of the stator windings.  You want less than 2 0hms and close to each other (any vehicle spec, I've never seen one for Ducati) between any two stator wires and infinity between any stator wire and the engine case. 

[ChrisK]

I'll get my hands on a second meter and see what it looks like.

Can you please explain how to check resistance of the stator wires?

[ChrisK]

Also, if I truly do have to replace the stator, is their oil behind the alternator cover? And, will I have to replace the alternator cover gasket?

[Speeddog]

I'll get my hands on a second meter and see what it looks like.

Can you please explain how to check resistance of the stator wires?

Here's a good Tutorial on how to diagnose charging systems:
http://www.ducatimonsterforum.org/index.php?topic=60660.0

Also, if I truly do have to replace the stator, is their oil behind the alternator cover? And, will I have to replace the alternator cover gasket?

Yes, there's oil behind the cover.

Either drain the oil or lean the bike over a good ways.

If the alternator cover *has* a gasket, you'll very likely need a new one, it'd be a good idea to replace it anyway.

Very likely it *does not* have a gasket, in that case all you need is some sealer (Yamabond, Ducatibond, Threebond, etc.)

[ChrisK]

I don't know if I know the terminology well enough for DP's tutorial to help answer my question.

I did do the part about testing AC voltage on each of the three wires, and couldn't come close to the 70V that I should see. (I will try a different multimeter tonight just to rule that possibility out).

My question now is, how do I test the resistance? Is it even necessary to test the resistance if the second multimeter also says I'm getting way less than the 70V?

DP's tutorial mentions fitting a DC Rectifier between the alternator wires and the battery to directly charge it. From what I gather, that allows you to test the alternator's ability to charge under load. Now, what kind of DC rectifier is he referring to, and where can I get one?

Thanks for being patient with me, I'm a quick learner with almost zero experience in this stuff.

[ducpainter]

I don't know if I know the terminology well enough for DP's tutorial to help answer my question.

I did do the part about testing AC voltage on each of the three wires, and couldn't come close to the 70V that I should see. (I will try a different multimeter tonight just to rule that possibility out).

My question now is, how do I test the resistance? Is it even necessary to test the resistance if the second multimeter also says I'm getting way less than the 70V?

DP's tutorial mentions fitting a DC Rectifier between the alternator wires and the battery to directly charge it. From what I gather, that allows you to test the alternator's ability to charge under load. Now, what kind of DC rectifier is he referring to, and where can I get one?

Thanks for being patient with me, I'm a quick learner with almost zero experience in this stuff.

That's Brad Black's work. I just copied and pasted it into the tutorials section

[Howie]

3 phase?  

Connector

      A __
            B __
      C __


A to B, B to C, A to C

[ChrisK]

3 phase?  

Connector

      A __
            B __
      C __


A to B, B to C, A to C

What are you telling me? Or asking me?

[Howie]

That is a (poor) illustration of the connector from the stator to the regulator (the three heavy yellow wires).  You are looking for less than 2 ohms between each connector on the stator side.  All readings should be close to each other.   

[ChrisK]

In an earlier post I explained that that connector doesn't exist anymore on my bike. It melted, so I hardwired the three wires from alternator to rectifier when I installed the new rectifier.

How do I use the multimeter to test this? I'm unfamiliar with what setting is needed in this particular situation, but if I had to guess, the one with the Ohms symbol?

Am I testing this when the bike is running? I think I would have to be, but I still have to ask.

Also, the same question again, is this test even necessary if I have two multimeters telling me that I'm getting half the AC volts I should be getting?

[Howie]

Ohms, bike off.  You need to get to the wires and isolate them from the regulator, which means snip.  That is the reason why I was never a fan of the eliminate the connector mod.   Ummm...if you are getting good voltage, no the resistance test is not needed.  I was under the impression your voltage at the stator was low.

[ChrisK]

Ohms, bike off.  You need to get to the wires and isolate them from the regulator, which means snip.  That is the reason why I was never a fan of the eliminate the connector mod.   Ummm...if you are getting good voltage, no the resistance test is not needed.  I was under the impression your voltage at the stator was low.

I'm not getting good voltage? Like half of what that tutorial posted above says I should get. Tutorial says I should see around 70V AC fairly quickly. Sitting at 6000 rpms I was still at 39V. From what I understand, that is way low. Or am I wrong?

[ChrisK]

I did the resistance test. First pair of wires was hovering right around .9 to 1. Second pair of wires hovered around .8 to .9. Third set of wires hovered around .4 to .5.

[ChrisK]

Okay now I'm confused and don't know whether I'm using the meter right. I did the voltage test again, holding the RPM's at 6000 and took a picture of two different multimeters. In each, positive probe was connected to one of the alternator wires and the negative probe was grounded. What am I doing wrong or what does this tell me?