charging system question(s)

[Ridetard]

Can anyone tell me what the output voltage should be from a stator?  2001 twin cam.   My battery droped to 12.1 volts.  When given a good charge. seems it wont charge over 12.9 vdc.   If memory serves me correctly and good battery fully charged without a load is 13.5 vdc.   Checked stator output,at 1500 rpm puts out 45vac.  Regulator is practically new. Im sure its a battery but want to cover all the bases first.  NO shorts to ground with the stator. 
The MOCO manual leaves a lot to be desired.   Provides no test procedure at all for the stator or regulator.

Any thoughts or comments is always appreciated.

R/T

[HotRock]

The correct battery voltage is approx. 12.8 VDC.   Battery will accept a surface charge from alternator or battery charger at 13.5 volts but will gradually bleed off.    If the battery was supposed to read 13.5 VDC at full charge, then it would be referred to as a 13.5 Volt battery.    Do you have any other indicators of a weak battery or charging system.

[Ridetard]

Thanks for the reply but what I am really looking for is info on the stator.  Specific resistance as well as voltage at idle and the rise rate.   But thanks just the same.

[HarleyFranco]

Ridetard,

I had a 01 softail, if I remember correctly the manual has a section of how to check the stator.  I think you measure the resistance between legs to see if one is shorted.  This is what happened to mine, first I checked the output and it was good, but didn't check from winding to winding and I replaced a regulator that I didn't need to.

Frank

[FSG]

The MOCO manual leaves a lot to be desired.   Provides no test procedure at all for the stator or regulator.

The ELECTRICAL DIAGNOSTICS Manual Part Number 99495-01 certainly does.  Do you have one ?

To test AC output, disconnect the regulator and connect an AC voltmeter across both stator sockets. Run the engine at 2000 RPM. The AC output should be as follows.

a. 38 amp (Low Output) models including FLHR, FLHR-I, FLHRC-I, FLHT, FLHTC, FLTR should read:16-20 VAC per 1000 RPM.

b. 45 amp (High Output) models including FLHTC-I,FLHTCU-I, FLTR-I should read: 19-26 VAC per 1000 RPM.

[Ridetard]

ok heres the deal.   1000 rpm 15.5 to 16 vac.......31vac@2000 rpm.   At idle, puts out 12.4 dc, 2000 rpm barely hits 12.7.  Seems to get worse as it heats up. No shorts to ground but am suspecting internal shorts in the windings.  Regulator was replace less then 3000 miles ado.   Im thinking stator.  OK teck dudes, what do you think?

RT

[HD/Wrench]

Is this a bagger?? look to see if there is oil in the plug between the stator and reg. Common issue and it will create huge issues.  I have seen it ruin the stator, and hurt the reg as well. Most times if you swap the stator the issue will be corrected however the reg many times is not far behind for going south. Relocate plug to elevated postion.

Your readings are on the low side ...

[straydog]

Ridetard,
You might read my post in General section, deka battery, for data concerning the issue of the battery and concerns regarding test instruments. That said, if your meter is accurate and you are reading less than 14vdc at the battery with the bike running above 1000RPM, you do have a problem. I would suspect the regulator first given the readings you post. Just to start with the easy stuff first, remove the battery from the bike or disconnect the negative cable and charge with a quality charger to see if your battery will take/hold a charge. Other than the readings you posted, are you having start/run problems?
Chris

[smoserx1]

You said:

1000 rpm 15.5 to 16 vac.......31vac@2000 rpm.

That sounds reasonable.  But earlier you had said:

Checked stator output,at 1500 rpm puts out 45vac.

That is not reasonable.

Right after you ride or charge the battery it will be 12.9 or so, and later it will drop a tenth or so.  At 2000 RPM I will get about 14.2 at the battery.

You are not basing any of this on what that in dash voltmeter says, are you?  You need a reliable voltmeter, and preferably a digital one, and take all your readings at the battery.

Now, like hotrock said, that battery is not going to read 13.5 on its own, so what makes you think you have a problem?  Is your battery failing to maintain a charge?  Are you having to push start or jump start your bike frequently?  Does your battery run down just sitting every few days? Is your battery very old?  Charge the battery fully and have it load tested.  If the battery is not operating properly, all these other tests are pretty much a waste of time in my opinion?

[hogmandon]

recently went through the same thing 06 RG pin to pin on stator wires I had 18 vac per 1000 rpm max was in the 50s pin to case open circuit, not grounded. drove me nuts then one day battery just died no warning. replaced it and all is well it was 4 1/2 yr old. I think battery was going bad inside and screwing with system.

[Admiral Akbar]

to case 0 ohms.

Then you may still have an issue..

I'd check the battery.. Load test it or if you can figure out how to get a current probe on the ground line look into measuring the charge and discharge current. If the battery is over 4 years old, I'd replace it.. Shorted cell will knock down the charging system output and fry the remaining cells.

Max

[Ridetard]

1.  Used a good digital VOM. not the dash gauge.
2.  The output of the stator varies as the the engine heats up.
3.  The battery has been load tested.  CRANKED  the engine for 60 seconds, the battery recovered fully..12.8vdc.
4.  Mr Garfield sir, with all respect due, I posted on the general board as not all members frequent the TC forum.
5.  Max, I stand correct...zero continuity to ground.(open circuit)
6.  Regulator was replaced less than 3000 miles ago..while replacing the regulator I found one lead from the stator shorted directly to ground as the insulation was worn due to vibration.  I bet that put a hell of a load on the stator.
7.  The out put from the stator (cold at 2000 rpm is 45vac...hot 31vac.)

Hope I satisfied everyone's critiquing.   
Didnt mean to create such a stir, was just looking for some help.


My original question WAS..the proper procedure for checking a stator.  What is the specific resistance of the coil? As well as the factory spec regarding AC output at various RPM.

Thanks just the same.

Happy fathers day to all of you.   

[Admiral Akbar]

Well if you can see that the output drops as the stator heats up, I'd say you've found the problem.. Probably the stator but I'd check the rotor also.. Make sure the magnets are in good shape..

Max

[FSG]

Hope I satisfied everyone's critiquing.

Ain't nothing wrong wit a good critique, it helps to get the facts out/

I read '0' or 'zero' continuity to ground as being a dead short to ground, you possibly mean to say there is no continuity or you have an infinity reading on you meter.  Digital VOM are good for a lot of things but they cant beat a good (Simpson) analog meter when it comes to resistance checks.



I'd suspect the stator, what you could do is replace the bikes battery with one from your car using jumper leads to see if the stator output when hot is still low.

Do you have the ELECTRICAL DIAGNOSTICS Manual Part Number 99495-01?

[straydog]

 :up:for MaxHeadflow statement. Some variance for temp would be acceptable but that is way too much change.
Ridetard, a DMM ohms measurement of the stator winding can only tell you open circuit or continuity. I do not know which test equipment would be needed to test the stator of an alternator. I know I use a specific piece of test equipment for coils to find the impedance in Henry.
Yup! Sounds like the battery is good.
7.  The out put from the stator (cold at 2000 rpm is 45vac...hot 31vac.)
I am not motor electrical expert but I would guess that as expansion in the windings occurs with the heat up, 1 or more winding loops are shorting together.
Just trying to help, Chris

[Ridetard]

Hope I satisfied everyone's critiquing.

Ain't nothing wrong wit a good critique, it helps to get the facts out/

I read '0' or 'zero' continuity to ground as being a dead short to ground, you possibly mean to say there is no continuity or you have an infinity reading on you meter.  Digital VOM are good for a lot of things but they cant beat a good (Simpson) analog meter when it comes to resistance checks.



I'd suspect the stator, what you could do is replace the bikes battery with one from your car using jumper leads to see if the stator output when hot is still low.

Do you have the ELECTRICAL DIAGNOSTICS Manual Part Number 99495-01?

zero continuity or the absence of continuity to ground= open circuit to ground
zero ohms to ground=dead short.
Huge difference in the two terms.  I have a degree that says so, with national honors.  Been a few years but dont think much has changed..

If I had the electrical diagnostics manual I wouldn't be asking.

[FSG]

zero continuity or the absence of continuity to ground= open circuit to ground
zero ohms to ground=dead short.

You are correct, my bad,  my degree says so also, sadly without "national honors" but it was a good result anyway.

If I had the electrical diagnostics manual I wouldn't be asking.

Well my last suggestion is you get one, the P/N was supplied earlier.

[Ridetard]

zero continuity or the absence of continuity to ground= open circuit to ground
zero ohms to ground=dead short.

You are correct, my bad,  my degree says so also, sadly without "national honors" but it was a good result anyway.

If I had the electrical diagnostics manual I wouldn't be asking.

Well my last suggestion is you get one, the P/N was supplied earlier.

LOL, I get busted by max all the time.  Its all good.

[barny7655]

Dont know about most folks but i always check voltage under load,and amps in the circuit , battery load tested first as that is the starting point of any electrical problem , then of course all wiring connections including grounds, and fuses, circuit breakers,wiring to and from regulator and to battery ,you have been advised of the VAC @ 1000, 2000,3000,from the alternator witch supplies only AC current , then it is changed to DC bye the rectfier,regulator, to a stable DC voltage with out load, and with load, EG head lights,most systems charge to 14.7 volts then through a grounding diaode switches excess DC voltage to ground,,what i would do is start at the battery , all wires checked , main alternator connector , if your not up to the job take it to a auto elect,will take him about 15 minutes to tell you the problem,my guess , a new stator assembly kit, a re check of regultor, cheers Barny

[glens]

6.  Regulator was replaced less than 3000 miles ago..while replacing the regulator I found one lead from the stator shorted directly to ground as the insulation was worn due to vibration.  I bet that put a hell of a load on the stator.
7.  The out put from the stator (cold at 2000 rpm is 45vac...hot 31vac.)

I've done some in-depth testing of (up to very large) power transformers, so I have some familiarity with this kind of stuff in general.

I'm thinking sitting here looking at a quick rough sketch that with the stator wired Delta I can get the system up and running with six diodes.  A single grounded stator lead would cause two windings to operate into a dead short for opposite halves of their AC waveforms.  That's not good, though certainly better than full-wave shorts.  It sounds as though you might have some compromised stator windings which get weaker with heat/use.

My original question WAS..the proper procedure for checking a stator.  What is the specific resistance of the coil? As well as the factory spec regarding AC output at various RPM.

I'll let you borrow the attachments pertinent to 09 Touring bikes, however applicable they may be for you, for some ideas.

I think I paid about $7 for the pair of shop and electrical manuals in PDF format somewhere off of ebay.  The internal links won't work for you in these excerpts.

[edit: the "stator_check" pdf file isn't coming back to me properly so I'm trying to replace it with another copy...]

[attachment removed after 60 days by system]

[barny7655]

Most rectifying diodes of alternators can adjust from 5 to 150 VAC times 6 ,of them 3 diodes  wave lengths - and 3 +then rectified and regulated to DC ,if there are any shorts in the wiring of any delta circuit it will either over charge, with no reference voltage to work on , or under charge through in sufficent AC current from one or more  of  the entire rectifing diodes from faulty  coils, thus abnormal amperage to charge the battery,this applys to most systems , havent pulled a regulator apart to see its solid state function on a HD,cheers , good post Barny

[Admiral Akbar]

Thought I understood alternators, regulators and rectifiers.. Don't have a clue as to what you just said..

Rectifiers don't adjust.. That are simply one way valves for current flow.

Not sure what you mean after that but if you have a short or open you could get voltage spikes.. Diodes (rectifiers) usually short unless you put way too much current through them. Then they blow like a fuse.. 

then it is changed to DC bye the rectfier,regulator, to a stable DC voltage with out load,

The rectifier /  regulator does not supply stable DC, it typically supplies 1/2 wave, Fullwave (HD), or 3 phase rectified DC. All have ripple. The battery acts as a capacitor to make the voltage stable.. The shunt type regulator on an HD probably does not have the loop response to make the output real smooth though it may be able to chop some of the ripple. The regulator provides a load to the alternator when the voltage is at the battery full level.

Max

[barny7655]

after the alternator passes VAC to the rectifier, the diodes can take a input of 5 to 150 VAC ,from the windings , the regulator then can adjust the VDC to charge the battery depending on the batteries signal voltage and demand of the load,i thought the VAC is none adjustable be fore the rectifying diodes , @1000 ,2000,3000 revs @ some where @ 40 vac,how can the regulater tell the windings before the rectifying diodes of what charge rate to charge,i thought the regulator takes battery voltage under load or not under load to adust voltage to charge ,thus shunting excess to ground, no the rectifier doesnt manage voltage to be charged at the battery,only to the regulator ,but it does manage DAC voltage to the regulator ,any ways may be on the wrong wave  length lol,Barny

[barny7655]

I did think that when we replace the regulator on our bikes ,it is a dual purpose solid state rectifier, regulator ,and pluged into the stator ,or some would say alternator, they are to me two different parts of the charging system, but cant work with out each other,, Barny

[Admiral Akbar]

You need to look at the output of the alternator and regulator with a scope.. You can see what is going on a little better.. An alternator is more a current source than a voltage source. That is one good reason to test them with some sort of load.. (though the manual has you measure it unloaded ).

The rectifier does not take the input from the alternator and convert the 150 volts AC, the rectifier conducts current from the alternator limiting it's output to say 12-14 volts (actually a little higher). You will not see 150 volts AC from the alternator unless there is something wrong in the system or it is disconnected.  On a HD charging system, the regulator is nothing more than a shunt (controlled short) to ground to limit the alternator output as to not over charge the battery.

some would say alternator

Alternator is a better term.. Stator is only part of an alternator.

Max