Wildly fluxuating voltages - Stator failure

[03HiYoSilver]

Kaitsdad,

Great News! Glad you solved the mystery. Thanks for the excellent post.

It looks like I have a shopping list to put together.....

 

[omnislash]

Kaitsdad,
Great News! Glad you solved the mystery. Thanks for the excellent post.

It looks like I have a shopping list to put together.....

As as i saying, how did you put the plug of the coil thru the engine and frame? I gave up trying for my case.

 

[ionbeam]

What worked for me...

Unplug the R/R connector and tie a stout string just below the connector. As you pull the connector through the frame the string will give you some control over guiding the connector and the string will be correctly routed through the frame to help pull the new connector back through.

There is a very stiff plastic shield between the engine and the frame with connector on the outside of the shield. With a little work it is possible to get the wires to slide down between the plastic shield and the frame until there is gap large enough for the connector to fit through. Once the connector is at the gap start pulling on the stator wires at the stator. You may want to keep a small amount of tension on the string to help guide the connector through the maze. Once you have the connector at the gap in the shield it goes pretty easy.

When you use the string to pull the new connector through the frame it will come out at the bottom gap and then need to be finessed back up between the plastic shield and the frame.

Patience and persistence.

The next two items to wrestle with are to keep the wire retainer bracket in the stator cover from touching the rotor after reassembly, and getting the rubber gasket that the stator wire passes through the cover properly placed and sealed.

 

[JamesK]

Well, I've R/R the Stator, and as can be seen from the pics it is certainly a "crispy critter" (my '07 FJR has 60k miles) so the readings I was getting (same as Hal & DaSpyder) were correct.

Now the bad news, whilst the charging system behavior has improved I'm certainly NOT seeing the complete fix that the other guys got. Now that the Stator is working according to specs I still don't get a steady 14.x VDC reading or any thing much over 13.6 VDC at the battery. Also the voltage "dip" under load is still present, albeit a little better than before at least it tries to recover after a short delay...

I've now been able to take readings from the R/R based on FSM test instructions and I am getting results that the FSM suggests R/R replacement is required. The output from the R/R (at the R/R contacts) is 16.2 VDC at 1,100 (idle) and 15.4 VDC at around 5k rpm. The FSM specifies 14 VDC exactly at 5K rpm or replace R/R.

Are there any other tests I can run on the R/R? Maybe borrow an R/R if someone has a spare just to test?

I am still running the original battery which is now 2yrs old. It seems to hold charge OK, and cranks the bike over without any perceivable difficulties. Is it still a good idea to change it?

 

[charismaticmegafauna]

I am still running the original battery which is now 2yrs old. It seems to hold charge OK, and cranks the bike over without any perceivable difficulties. Is it still a good idea to change it?

Replacing a known good battery with another known good battery avails you nothing....

Known good battery = 12.8 V at rest; holds it's charge a reasonable length of time (month/s?); and doesn't drop too much voltage at cranking (couple volts? -- there's a test for this....).

 

[JamesK]

I am still running the original battery which is now 2yrs old. It seems to hold charge OK, and cranks the bike over without any perceivable difficulties. Is it still a good idea to change it?

Replacing a known good battery with another known good battery avails you nothing....

Known good battery = 12.8 V at rest; holds it's charge a reasonable length of time (month/s?); and doesn't drop too much voltage at cranking (couple volts? -- there's a test for this....).

Agreed, and I guess I should try not plugging it into a battery tender all the time, to see how well it holds the charge.

My thinking was along the lines of: if the battery is a little funky it might not be able to accept a charge from the R/R at the required rate/speed and Amps, thus forcing the R/R to "dump" the charge... I was thinking this because the R/R outputs are showing a much higher Voltage than what I see at the battery.

 

[Fred W]

Actually, 14V is what you want, but your measurements are higher. That would say you'd be over charging your battery. Your voltmeter is telling you that you are undercharging it. Why the big discrepancy? Is your voltmeter actually connected directly to the battery?

 

[JamesK]

Actually, 14V is what you want, but your measurements are higher. That would say you'd be over charging your battery. Your voltmeter is telling you that you are undercharging it. Why the big discrepancy? Is your voltmeter actually connected directly to the battery?

Yes a Fluke77 meter with the probes on the battery terminals and only low beams on.

I am not an expert on battery symptoms, so any experts out there please chip in. Can a flaky battery be telling the R/R to "dump" the charge because it can't accept it at the rate/Amps the R/R is trying to feed it?

 

[Fred W]

No, but a battery can draw too much charging current from the R/R and cause a low voltage reading.

Are you sure that there are no other big loads on the charging system? No aux lights or heated grips or anything?

It's not unusual to see a lower charging voltage to the battery as the load increases.

 

[JamesK]

No, but a battery can draw too much charging current from the R/R and cause a low voltage reading. Are you sure that there are no other big loads on the charging system? No aux lights or heated grips or anything?

It's not unusual to see a lower charging voltage to the battery as the load increases.

Fred, I have all these farkles but they are all OFF during the test. Now when I turn on the Solteks for example, the DVM drops to 12.6-12.8 VDC range, then slowly climbs up to around 13.1-13.3ish VDC (these readings are shown on both the Fulke DVM and the Datel).

I've gone ahead and ordered a new WestCo battery from Jeff at Bike Effects since this is not a warranty part and mine is old enough for that to not be a total waste of money.

The OEM battery reads around 12.4-12.6 VDC with just the ignition switched on (bike not started yet), this is after a full charge on a battery tender.

 

[ionbeam]

...My thinking was along the lines...battery is a little funky it might not be able to accept a charge from the R/R at the required rate/speed and Amps, thus forcing the R/R to "dump" the charge... I was thinking this because the R/R outputs are showing a much higher Voltage than what I see at the battery.

If you are measuring (example) 14.3 volts at the output terminals of the R/R but are measuring 13.8 at the battery terminals there is too much resistance in the wires and connections between the R/R and the battery. Each connection/junction may only cause a small voltage drop but they add up to the missing volts at the battery. The largest voltage drop in my motorcycle is across the main fuse.

 

[JamesK]

...My thinking was along the lines...battery is a little funky it might not be able to accept a charge from the R/R at the required rate/speed and Amps, thus forcing the R/R to "dump" the charge... I was thinking this because the R/R outputs are showing a much higher Voltage than what I see at the battery.

If you are measuring (example) 14.3 volts at the output terminals of the R/R but are measuring 13.8 at the battery terminals there is too much resistance in the wires and connections between the R/R and the battery. Each connection/junction may only cause a small voltage drop but they add up to the missing volts at the battery. The largest voltage drop in my motorcycle is across the main fuse.

Thanks Alan, is it really possible/likely to loose nearly 2 volts through the main fuse? I guess a good test would be to try to get a reading from the plug side of the R/R while it's still connected to the bike since a similarly good reading from there would eliminate the R/R as being a problem? I don't really know how to do that without splicing into the R/R plug wires which is not the optimal solution

 

[Fred W]

Hang on a second... When you are measuring the R/R output at 15.4V, is that with the R/R output connector disconnected (and therefore no load on it)?

What does it measure if you back-probe the connector with it still connected to the harness and charging the bike?

 

[JamesK]

Yes, per the FSM instructions.

I was thinking out loud based on Alan's comments about voltage drops to the battery.

 

[Fred W]

Yes, I think Alan was under the impression that the R/R voltage is higher than the battery voltage when under load. That's why he recommended checking the cable between them (including the main fuse). It is curious that your R/R is running high when unloaded, and that may indicate an R/R problem, but it doesn't necessarily explain why the charging voltage to the battery is low under normal load.

The way the R/R works is that the Stator puts out more power than you need (under normal conditions). The Rectifier turns the AC to DC and the Regulator adjusts the output to the nominal 14VDC. If there is excess voltage the Regulator dumps that. So, with your unloaded R/R voltage being higher then 14V one would expect the loaded voltage to also be higher, assuming that there is a single problem and it is with the regulator (as their appears to be).

 

[dcarver]

Update -
Well, I got it put back together today -

Started her up ......

And dead on stable voltages. It was most certainly the stator.

So - to those of you with 'dancing' voltage read outs - you might want to really watch it - and make sure your towing service is up to date.

Good job Hal! Now, the next step, to rewind the old stator?

Ya know, it would be kinda fun to play with an old stator - but it went back to MammyYammy.

Don, don't you have a "dancing Nancy" stator? And there's also Silent - Ray, what's your's like?

My dancing Nancy is only doing a 2 step, not a complete waltzing Matilda. :lol:

When cold, at idle, normal house load, I see 14.1, 14.2, 13.9, about a .3 .4 max VDC swing. I attribute that to noise.

When hot, the voltage actually stabilizes a bit, I see maybe a .1 sometime .2 swing.

Additionally, when loaded, the circuit appears more stable. Turn on the Solteks and she's rock solid.

For now, I'm just going to keep on running what I have.. :yahoo:

 

[kaitsdad]

Update -
Well, I got it put back together today -

Started her up ......

And dead on stable voltages. It was most certainly the stator.

So - to those of you with 'dancing' voltage read outs - you might want to really watch it - and make sure your towing service is up to date.

Good job Hal! Now, the next step, to rewind the old stator?

Ya know, it would be kinda fun to play with an old stator - but it went back to MammyYammy.

Don, don't you have a "dancing Nancy" stator? And there's also Silent - Ray, what's your's like?

My dancing Nancy is only doing a 2 step, not a complete waltzing Matilda. :lol:

When cold, at idle, normal house load, I see 14.1, 14.2, 13.9, about a .3 .4 max VDC swing. I attribute that to noise.

When hot, the voltage actually stabilizes a bit, I see maybe a .1 sometime .2 swing.

Additionally, when loaded, the circuit appears more stable. Turn on the Solteks and she's rock solid.

For now, I'm just going to keep on running what I have.. :yahoo:

Don, based upon those readings, you don't have a problem.

Should your stator start to fail, you'll see voltages swinging from 14.2 down to 11.5 and everywhere in between. Ain't pretty.

 

[JamesK]

...My thinking was along the lines...battery is a little funky it might not be able to accept a charge from the R/R at the required rate/speed and Amps, thus forcing the R/R to "dump" the charge... I was thinking this because the R/R outputs are showing a much higher Voltage than what I see at the battery.

If you are measuring (example) 14.3 volts at the output terminals of the R/R but are measuring 13.8 at the battery terminals there is too much resistance in the wires and connections between the R/R and the battery. Each connection/junction may only cause a small voltage drop but they add up to the missing volts at the battery. The largest voltage drop in my motorcycle is across the main fuse.

Based on Alan's comments I took some readings of the resistance b/w the R/R plug wires to the rest of the bike:

Batt+ to R/R Red wire: 0.3-0.4 Ohms

Batt- to R/R Black wire: 0.2-0.3 Ohms

* Batt- to Bolts on the Triple Tree: 0.2-0.3 Ohms

* Batt- to Engine Case: 0.3 Ohms

* Batt- to Frame Bolt (tail section): 0.3 Ohms

I've not checked against the FSM requirements for these readings, but they certainly don't look bad too me.

 

[Silent]

Update -
Well, I got it put back together today -

Started her up ......

And dead on stable voltages. It was most certainly the stator.

So - to those of you with 'dancing' voltage read outs - you might want to really watch it - and make sure your towing service is up to date.

Good job Hal! Now, the next step, to rewind the old stator?

Ya know, it would be kinda fun to play with an old stator - but it went back to MammyYammy.

Don, don't you have a "dancing Nancy" stator? And there's also Silent - Ray, what's your's like?

My dancing Nancy is only doing a 2 step, not a complete waltzing Matilda. :lol:

When cold, at idle, normal house load, I see 14.1, 14.2, 13.9, about a .3 .4 max VDC swing. I attribute that to noise.

When hot, the voltage actually stabilizes a bit, I see maybe a .1 sometime .2 swing.

Additionally, when loaded, the circuit appears more stable. Turn on the Solteks and she's rock solid.

For now, I'm just going to keep on running what I have.. :yahoo:

Don, based upon those readings, you don't have a problem.

Should your stator start to fail, you'll see voltages swinging from 14.2 down to 11.5 and everywhere in between. Ain't pretty.

Mines not that far gone either. I think mines just doing the Hokie Pokie. My swings run around a half volt to a volt I've seen swings as far as 14.2-13.2 but not holding either for extended periods. For now, I'm in a "wait and see" mode. I'll keep an eye on it and if it gets worse, then I'll actually do something