Erratic red charging light behavior - 86 r80

Discussion in 'Old's Cool' started by Uncle Pollo, Dec 27, 2011.

  1. Uncle Pollo

    Uncle Pollo Long timer

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    Off idle - flickering red.

    Sometimes cuts off 1200ish

    sometimes higher.

    Brush pack?
    #1
  2. Quasi1960

    Quasi1960 Been here awhile

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    Probably.
    #2
  3. Uncle Pollo

    Uncle Pollo Long timer

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    If not; what else?
    #3
  4. Wirespokes

    Wirespokes Beemerholics Anonymous

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    Perhaps nothing is wrong. If it goes off and stays off, I wouldn't worry about it. Some of the differences are state of battery charge and temperature. The voltage regulator regulates differently when hot than cold.

    If it goes out, and stays out, by 1200 RPM, there's nothing to worry about.
    #4
  5. Uncle Pollo

    Uncle Pollo Long timer

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    It's been -7 celcious consistently.
    #5
  6. eepeqez

    eepeqez Long timer

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    It's not like its a major voyage of discovery to get far enough in to see what they're like!

    Flickering does suggest dodgy continuity which worn brushes will certainly provide.

    Other possibilities include:
    Field (rotor) or stator winding faults, but these tend to go bad and stay bad, not flicker.
    Voltage regulator failing - but it's an electronic regulator, not mechanical, so they're usually pretty reliable.
    Loose connection anywhere in the alternator wiring, especially voltage regulator, warning lamp, brushes (ah, we'r back where we started).
    Loose battery terminal.
    #6
  7. Speedzter1969

    Speedzter1969 Ride, wrench, repair

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    My experience has been this:
    One night, whilst going to meet a friend for a ride down to NYC, the GEN light started to flicker. The diode board had been replaced a year prior, but this was different. Get to his house, pull off the front cover and checked brushes, connections, etc. The voltage also dropped to about 12.5 when the light was flickering. We go off on down to NY, and no problems. Next day same thing. I replaced the brushes, which were fine, and didn't help. Swapped out stator from other bike, as well as voltage regulator. Last thing was the rotor, ordered up a new one, and that was it.
    I hear that once rotors "go", they "go". Mine was intermittent, so no one believed that was it. My gut told me it was.
    I now have a pretty much new electrical system now that will probably last another 20 years.
    When the diode board went, the GEN light glowed dimly at night. I am becoming well-versed in these electrical gremlins. Seems all my bikes have had them at one point or another.
    Good luck!:D
    #7
  8. Uncle Pollo

    Uncle Pollo Long timer

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    Rotor ... mmhm .... where the hell it is?
    #8
  9. robtg

    robtg Been here awhile

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    Ask Newt.
    #9
  10. Uncle Pollo

    Uncle Pollo Long timer

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    Aw ... I will change my avatar and signature soon.

    It's a prank about the least likely and able being my favorite.
    #10
  11. Boxer Metal

    Boxer Metal Mad Scientist

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    Drink more beer and close one eye:) Your probably fine.
    #11
  12. bereahorn

    bereahorn Long timer

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    :lurk
    #12
  13. Uncle Pollo

    Uncle Pollo Long timer

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    It was the brushes
    #13