Paper-ing my Stator: Or... Electricity confuses me

[Guest]

OK, it's finally happened, no more charging.

Background
I had resolved a previous issue a year or two ago by replacing the R/R, and that's been going strong since then, but in the last few weeks I noticed labored cranking, puzzling power loss/rough running, turn signals that wanted to burn steady instead of blinking, and then one day the engine idled down to a stop at a stop sign (wait, dear bike, too literal!) thankfully less than a mile from home.

Charging the battery fixed it all, but only for about a day at a time. (This bike is my daily driver.)

In anticipation of eventual failure, I had bought a stator when I bought the R/R, but I didn't want to fix what wasn't broke at the time. Now that I'm not charging again, I was tempted to just swap it in, but thought I should take some measurements first and make sure it wasn't something else.

That's where I got stuck, because I'm a total electricity noob.

What I've done

Was uncertain which way to connect the test leads to my meter (well, I learned the hard way years ago not to use the 10A connection). So, I hooked them up so that when I measured across the battery with the red lead on "+" and the black lead on "-" I got a positive rather than a negative voltage.

So then I started in on the Stator Papers flowchart.

With red lead to + and black lead to -...
Battery voltage at 2500rpm: 12.2V
Battery voltage at 5000rpm: 12.8V

If I had doubted that I wasn't charging, this took care of my doubt.

Then it got confusing...

With the engine at idle (around 1K rpm)...
Black lead to "+", red lead to R/R red output wire (still connected - I pushed the lead into the connector): -.83V

Unsure if I should pay attention to the minus sign for evaluating if this was more or less than 0.2V listed in the stator papers, I went on to the next test

Red lead to "-", black lead to R/R Black/White output wire: .01V

Now actually, I got one of those cool R/R units with a neg lead that was long enough to reach the "-" batt terminal, and that's where I had connected it, so I was basically reading voltage between the batt terminal and the bare R/R wire just past the lug - didn't expect to read much voltage.

Main questions:

1. Do I seem to be doing this right so far?
2. Is -.83V more or less than 0.2V?

Thanks guys!

[BassCliff]

Hi,

With the engine at idle (around 1K rpm)...
Black lead to "+", red lead to R/R red output wire (still connected - I pushed the lead into the connector): -.83V

This means you have almost a 1v loss due to corrosion/bad connections between the r/r output and the battery(+). Not a good thing. Clean up your wiring harness, grounds, all electrical connections, etc.

Red lead to "-", black lead to R/R Black/White output wire: .01V

This measures the voltage loss on the ground circuit. This measurement is not bad. But I run the ground wire from the r/r directly to the negative battery terminal to eliminate any loss through the frame or bad connections. In the stock form the ground wire for the r/r is usually connected to the battery box, a lousy ground point.

Have you tested the AC output of the stator legs? This will be most telling. There's a stator test guide with pictures on my website that make the Stator Papers a little more understandable.


Thank you for your indulgence,

BassCliff

[posplayr]

OK, it's finally happened, no more charging.


With the engine at idle (around 1K rpm)...
Black lead to "+", red lead to R/R red output wire (still connected - I pushed the lead into the connector): -.83V

Unsure if I should pay attention to the minus sign for evaluating if this was more or less than 0.2V listed in the stator papers, I went on to the next test

1. Do I seem to be doing this right so far?
2. Is -.83V more or less than 0.2V?

Thanks guys!

It sounds correct, and as Cliff said you have big voltage drops between the R/r(+) and the Battery(+). If you have a 20 amp in line fuse, you can put it directly from the R/R output to the battery (+) and see if it helps the problem. Your charging voltages should increase immediately.

That being confirmed you can figure out where the bad connections are; you need to use a contact cleaner that will get into the crimps and dissolve the corrosion.

The 0.84V means that you are pushing current and your stator is OK at the moment, but it also means that the R/R is thinking that the battery is happy and is shorting the stator more that it should to keep the battery voltage from being too high. Do not let this persist..

[Roostabunny]

Mr. Basecliff, sir! Thank you. Glad to see you're as active here as ever. Sorry I've been rather absentee, myself.

I read (or tried to read) the supplemental paper from PosPlayr, and though I'm sure it's very informative, it seems geared to those for whom the Stator Papers were not technical enough.

I forgot about your testing PDF though - that will be very helpful, I think. It's already reminded me how simple it actually is.

[posplayr]

Mr. Basecliff, sir! Thank you. Glad to see you're as active here as ever. Sorry I've been rather absentee, myself.

I read (or tried to read) the supplemental paper from PosPlayr, and though I'm sure it's very informative, it seems geared to those for whom the Stator Papers were not technical enough.

I forgot about your testing PDF though - that will be very helpful, I think. It's already reminded me how simple it actually is.

Sorry, I need to re organize the supplements and give a clear process for the debugging process.

[Roostabunny]

Thank you, Posplayr!

Interesting - sure glad I slowed down instead of just slapping the new stator in there. More than the normal amount of wet-weather riding lately - maybe that pushed some of those stressed out 30+-year-old bullet connector over the edge.

Noob question - this "voltage drop", are you guys saying that there's more voltage coming from the R/R than what's getting to the battery? Hence the deduction that there's actually voltage coming from the stator? It's getting to the R/R, and sent to the batt, but it's just not getting there?

Is De-oxit an OK product to start with? Though I think I have enough spade connectors to redo all the R/R connections - it's just a question of time.

And "do not let this persist" because the R/R is shunting even more voltage back into the stator than normal? Creating even more potentially stator-damaging heat? Just making sure I understand your meaning.

Edit: And don't think I'm ungrateful for the supplemental material! It's obvious that you've got deep knowledge there but like I tell all the (many) engineers I work with - it's hard to remember what it's like not to know what you know.

[posplayr]

Thank you, Posplayr!

Interesting - sure glad I slowed down instead of just slapping the new stator in there. More than the normal amount of wet-weather riding lately - maybe that pushed some of those stressed out 30+-year-old bullet connector over the edge.

Noob question - this "voltage drop", are you guys saying that there's more voltage coming from the R/R than what's getting to the battery? Hence the deduction that there's actually voltage coming from the stator? It's getting to the R/R, and sent to the batt, but it's just not getting there?

In the simplest of terms, the R/R uses the voltage it senses at it's terminals to determine whether to allow more current to flow to the battery or to hold back. If there is resistance between the R/R(+) and Battery(+) then there is a voltage drop that fools the R/R into thinking there is more battery voltage that there actually is. So it robs the power from the battery and instead keeps the stator shorted for longer in order to accomplish this. Not good. And you were doing the test at 1K RPM as suggested by the stator pages. I revised them to do this at 5000 RPM when the current flow is maximum. It makes it worse.

Part of the diagnosis is that when the charging voltages are low (as yours are) but there are high voltage drops between R/R and battery it points to bad connections.

If the charging voltages are down but there are not any big voltage drops then it is more likely a stator that is not creating the power required. It takes current to create these voltages, so even if there is resistance without the charging current the voltage drops will not be there.

Is De-oxit an OK product to start with? Though I think I have enough spade connectors to redo all the R/R connections - it's just a question of time.

And "do not let this persist" because the R/R is shunting even more voltage back into the stator than normal? Creating even more potentially stator-damaging heat? Just making sure I understand your meaning.

Yes De-oxit is excellent. If I have never used it, but from what I read it works very well. I do need to get some. I have used Naval jelly to clean corrosion then dielectric grease to stop corrosion of the new bare copper.

Edit: And don't think I'm ungrateful for the supplemental material! It's obvious that you've got deep knowledge there but like I tell all the (many) engineers I work with - it's hard to remember what it's like not to know what you know.

Yes I just noticed you are in Huntsville; I've been there a few times and it is a huge facility and more engineers concentrated in one place than I have ever seen.

[Roostabunny]

Sorry about the image quality (in which the cruddy state of my connectors is never-the-less obvious), but I wanted to check that the three wires (blue stripe, yellow stripe, and green stripe) on the right are the stator wires?

And I think that I'd be OK to outfit all of these with spade connectors if I have them handy?

[Roostabunny]

OK, Posplayr, starting to make sense and more sense. And I have both DeOxit and Di-electric grease - just overdue to attack this project.

Yes I just noticed you are in Huntsville; I've been there a few times and it is a huge facility and more engineers concentrated in one place than I have ever seen.

Yeah, Huntsvegas is a strange and wonderful place. After a few years here I've taken to assuming each new person I meet has a PhD, no matter how much they may sound like a farmer to my Yankee ears. And I work for a commercial company (as opposed to a government contractor) but we're still in electronics, so I'm lousy with people who've forgotten more about electricity than I'll ever know.

[posplayr]

Sorry about the image quality (in which the cruddy state of my connectors is never-the-less obvious), but I wanted to check that the three wires (blue stripe, yellow stripe, and green stripe) on the right are the stator wires?

And I think that I'd be OK to outfit all of these with spade connectors if I have them handy?

Most of those dark connections looks like heated connections

The 3 stator wires will head up into the chain area and then the started cavity.
Rather than screw around with spade connections I just strip back the wire wrap it together good and solder. Don't forget the shrink tubing before soldering. There is usually plenty of length to do that several times.

[Roostabunny]

Well, I think it might be the end of the road for my stator.

Cleaned up the stator connections and the red R/R lead connection, and while I was at it decided to check resistance.

I set the meter for 20 ohms

Across all legs -
1.9 ohms
2.0 ohms
2.1 ohms

That 2.1 gave me pause, but I wondered if it might be within the error of the meter.

Anywho, when I measured resistance to ground it seemed like it might be moot, since I got the same readings - all between 1.9-2.1 ohms.

I think this indicates a short to ground, so is there any point in checking stator output at this point?

[posplayr]

Well, I think it might be the end of the road for my stator.

Cleaned up the stator connections and the red R/R lead connection, and while I was at it decided to check resistance.

I set the meter for 20 ohms

Across all legs -
1.9 ohms
2.0 ohms
2.1 ohms

That 2.1 gave me pause, but I wondered if it might be within the error of the meter.

Anywho, when I measured resistance to ground it seemed like it might be moot, since I got the same readings - all between 1.9-2.1 ohms.

I think this indicates a short to ground, so is there any point in checking stator output at this point?

Did you put the meter leads together to see if you get zero ohms?

Doing the 5K rpm tests leg to leg and leg to case are the most reliable tests.

[tom203]

"I set the meter for 20 ohms"

You got a meter that has a 20 ohm range/scale? most of cheapies start at 200 ohms and some have problems reading 1 ohm

[Roostabunny]

"I set the meter for 20 ohms"

You got a meter that has a 20 ohm range/scale? most of cheapies start at 200 ohms and some have problems reading 1 ohm

It is indeed a cheapie (HF special), Tom203 and I'm really not too confident that I'm using it correctly. Not only that, but whatdya know... I had it set at 200 because there's no dang 20 ohm setting. So I'm apparently confused by both electricity and, more distressing, by reading.

I did put the leads together, and I feel stupid admitting this, but I didn't get zero on this "200" setting. I got... wait for it... 1.9 Ohms.

So, let me do all these over again, but where should I set the dial?

[Roostabunny]

BTW, I did measure leg-to-leg stator voltage, too, at about 4000 rpm and got about 13V from all three legs.

Oh, and I had set the meter for 200 VAC for this measurement, just in case I borked that up too.