How do you check if the alternator is functioning properly.

Discussion in 'Parallel Universe' started by EnderTheX, May 8, 2011.

  1. LukasM

    LukasM Long timer

    Joined:
    Nov 15, 2006
    Oddometer:
    5,456
    Location:
    On a RTW ride - currently touring the U.S.

    That is not the case unfortunately, a MOSFET R/R will do nothing for stator life. It's just a more efficient switching circuit, so it heats up less. That is good on bikes that regularly burn out R/Rs, but not in our case. Guess where that extra power gets dissipated instead - the stator.

    The type that will help is a series type regulator that I mentioned above. I explained it in another thread on stators here in the parallel universe how it does it by reducing the actual power being produced, will post it again when I have access to a computer.

    Btw the rating of a R/R refers to the total power it can deal with, not each of the wires.
    #41
  2. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    Gary:
    In terms of power rating, 30 amps is roughly what we would need, the charging system on the F800GS is spec-ed at 400 watts - watts is Voltage x current so at (say) 13 volts, 400 watts is indeed ~30 amps.

    Nice article here that explains how crappy shunt regulators (wait ... I meant "cost-effictive" ) differ from the more advanced designs (see the section "Active regulators").

    http://en.wikipedia.org/wiki/Voltage_regulator

    One key thing I think we should all be doing is making sure that the frame/ground connection to our regulators is clean and solid ... if not, the regulator will quickly fry.

    Other than replacing the regulator with a more advanced design, or somehow improving the stator windings or keeping them cooler I'm not sure what else we can do...............
    #42
  3. itsatdm

    itsatdm Long timer

    Joined:
    Jun 19, 2004
    Oddometer:
    5,386
    Location:
    Nor Ca.
    I though the Mosfet RR was a relay type. Trying to educate myself, I read on the internet (must be true) that is had the ability to shut down a segment of the stator if all the amps were not needed.

    It would be nice to see an electrical diagram to determine if all the bikes power comes off the battery or are parts of the systme fed directly from the R/R.

    Still have not heard whether Canbus would prohibit some other option.
    #43
  4. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    Gary:

    Here's the scematic .... I figured it would be more complicated, but really there is not much to see once you've seen it .... :lol3

    3 wires from stator to R/R then a pair of wires wires from Regulator to each terminal of the battery

    Attached Files:

    #44
  5. itsatdm

    itsatdm Long timer

    Joined:
    Jun 19, 2004
    Oddometer:
    5,386
    Location:
    Nor Ca.
    Thank you. It looks simple enough. All roads lead to the ECU
    #45
  6. ebrabaek

    ebrabaek Long timer

    Joined:
    Jan 12, 2010
    Oddometer:
    5,475
    Location:
    Grand Valley, Colorado
    It would be interesting to see a diagram of the inside of the RR....... Anybody have one?????:thumb:thumb

    Erling
    #46
  7. LukasM

    LukasM Long timer

    Joined:
    Nov 15, 2006
    Oddometer:
    5,456
    Location:
    On a RTW ride - currently touring the U.S.
    I haven't seen a diagram but due to the part number I am quite sure that it's just a regular Shindengen shunt type R/R like 95+% of other bikes have - prefix SH. Some of the higher tech jap bikes get the MOSFET ones stock - prefix FH.
    #47
  8. MoToad

    MoToad Been here awhile

    Joined:
    Jul 4, 2008
    Oddometer:
    928
    Location:
    Nelson BC, fer now.
    I don't think I chimed in here about my stator replacement.(last week) Still had three months warranty left so I got in under the wire. I guess it was losing it slowly for some time now as I can remember some low battery events like engine turning over and locking at TDC well over a year ago. Figured it was just the orig. battery slowly giving up and when it increased a couple of months back, I replaced it. Then the new one lost charge in a few days so I looked further to see my stator output was 11.9 V. Anyhoo, all is well and happy again as I got a service at 50,000kms., stator replacement, valve check and new cover gasket replacement (it was leaking too) all for 2 bills. The valves were fine with no need of adjustment and the mechanic, who used to fix a lot of Ducatis back in the day with stator burnouts said they solved the problem by running a ground wire from the regulator to the frame. He did specify it is key to grind away the non conductive coating on the regulator to get a good ground. Same for the frame, of course. Hope this works and I am not putting out $800 plus for one of these in another 50000. And I am surprised that BMW is not acknowledging this problem and showing a fix on newer models.
    #48
  9. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    Toadride:
    I can see how a bad ground might cause early death of the regulator, but given the design of our systems where the stator is (as I understand it) ALWAYS putting out 100% of what it can give I don't see how a bad ground could cause stator failure ... :huh

    I'm not saying your tech. has it wrong ... there's a damn good chance I don't know WTF I'm talking about ... :lol3
    I do think a bad ground could cause lots of other "interesting" problems, so I'm adding a check to my maintenance sheet to check the R/R ground once a year or so...
    #49
  10. ebrabaek

    ebrabaek Long timer

    Joined:
    Jan 12, 2010
    Oddometer:
    5,475
    Location:
    Grand Valley, Colorado
    I fully agree that a bad ground can severely diminish the rr function.
    It's easy to speculate how the rr is constructed.... And personally I don't have an idea how th 8 gs rr look on the inside.
    But most like Lukas mentioned are just a bunch of diodes which does the rectification....
    But if you have a bad ground.... The rr can't dissipate the exess energy to ground.... And it's gonna go somewhere.
    I will have a look at my grounding tomorrow....

    Erling
    #50
  11. MoToad

    MoToad Been here awhile

    Joined:
    Jul 4, 2008
    Oddometer:
    928
    Location:
    Nelson BC, fer now.
    Don't believe I mentioned anything about a bad ground. The mech just said that adding the extra ground at the regulator fixed the Duc problems with burning up stators. I think we are both hoping it takes care of any future problems with mine.
    #51
  12. ebrabaek

    ebrabaek Long timer

    Joined:
    Jan 12, 2010
    Oddometer:
    5,475
    Location:
    Grand Valley, Colorado
    True.... You did not..... But the stator have to be grounded........ That is how it dissipates the heat.... Only reason it need a "extra one" is if the factory one is bad...... :freaky Some RR`s are grounded via a chassis mount....In which same apply. So you wan`t to check the grounding in general...... But adding another wire would work as well....as long as it`s grounded.....:thumb:thumb

    Erling
    #52
  13. itsatdm

    itsatdm Long timer

    Joined:
    Jun 19, 2004
    Oddometer:
    5,386
    Location:
    Nor Ca.
    Maybe another reason to check contact points. R/R housing is aluminum, the chassis is steel = galvanic corrosion. The contact point on the frame is some type of insert, maybe a means to combat corrosion.
    #53
  14. TheCowboy

    TheCowboy back in the saddle again

    Joined:
    Feb 15, 2008
    Oddometer:
    621
    Location:
    The frozen tundra - Minny Sota
    Today, 1/2 way into a month-long ride - the display blanked, then came on again - then off, then on. Stopped for gas in the middle of nowhere New Mexico - would not restart. Jumped battery to start - raced 12 miles to Auto Parts store - rechared battery - raced 100 miles to Durango CO. Now stuck here. Will try to make the BMW dealer 20 miles to the West tomarrow on just what is left of battery.... oh yes, I am at 50,400 miles. First failure on bike. I am sure it is the stator. I think it will be expensive.

    TheCowboy
    #54
  15. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    Cowboy ... that sucks.... :cry

    Not sure if you've been following the threads on this, but if you buy from BMW you get a new flywheel in the "kit" not sure why ... I would not expect the permanent magnets in the flywheel to be much of a problem .... but with the flywheel it bumps the price quite a bit apparently to some $800 or so...

    If it is the stator, a competent shop can re-wind your stator for you saving you some cash ... price ~$150.

    Apparently the mechanics of replacement are pretty simple.... key thing is to torque the side cover bolts in proper sequence when re-assembling. I can post that sequence ... if you need it let me know!
    #55
  16. TheCowboy

    TheCowboy back in the saddle again

    Joined:
    Feb 15, 2008
    Oddometer:
    621
    Location:
    The frozen tundra - Minny Sota
    JR, yes, please give me that sequence, also, how do you unplug the wires from the stator? I have cover off but cannot figure out how the wires come off so I can pull stator completely off... thanks

    TheCowboy
    #56
  17. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    Ok ... if I did this correctly there should be an attachment showing how the stator wiring is removed ...
    basically from the back of the regulator is seems.......

    Attached Files:

    #57
  18. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    next installing the (repaired) stator:

    Attached Files:

    #58
  19. JRWooden

    JRWooden Long timer

    Joined:
    Jul 5, 2008
    Oddometer:
    4,689
    Location:
    The great state of confusion
    next ... sequence for bolting up the cover below...

    THEN install all the other crap you took off,
    make sure the regulator is FIRMLY grounded / bolted to the frame...
    check oil level etc....

    Attached Files:

    #59
  20. LukasM

    LukasM Long timer

    Joined:
    Nov 15, 2006
    Oddometer:
    5,456
    Location:
    On a RTW ride - currently touring the U.S.
    That sucks... Rick's Electrics can probably turn a rewind around in a day or so if you give them advance notice ($165 incl. return shipping).

    And the wires stay attached to the stator, so just unplug the connector at the other end.
    #60