battery volts at idle

Discussion in 'Dyna Models' started by rjsogard, Nov 22, 2009.

  1. rjsogard

    rjsogard Member

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    Hello all

    well i had the dreaded 06 stator rotor blowup problem now i have no charging at idle but as i turn the throttle the volts go to 13.40 but at idle it looks like the battery is discharging at 12.45and is going lower in volts. heres what the dealer changed,

    1. battery
    2. alt stator assy
    3. volt reg
    4. volt reg twice

    What would cause the battery to discharge at idle but rise as i turn the throttle the engine light and batt light will come on at idle now its intermitting
    thanks
     
  2. 2000classic

    2000classic Active Member

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    Is idle speed at proper setting? Too low could cause this.
     
  3. glider

    glider Veteran Member

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    I agree, idle should be between 950-1050 to support all systems on the bike and still charge the battery.
     
  4. Hoople

    Hoople Account Removed

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    Rich,
    One other thing that would give you these classic symptoms (low charge @ idle and what looks to be charging @ hi RPM) would be 1 of the 3 phases not working or contributing.
    If you have access to a scope I can give you some details on how to check it. Even if you just have a Good DMV you still can take some course measurements. I see you may not be able to post. E-mail me if I can be of some help.
     
  5. Drumrguy

    Drumrguy Account Removed

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    That sounds about right for battery voltage at idle. Are you having any issues with the bike not starting after you run it?
     
  6. Hoople

    Hoople Account Removed

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    Just a quick comparison test to my bike you may want to try.. With the engine idling, look at the brightness of your headlight/ with Hi beam on, reflecting on a wall. While watching the light, I can kill my engine using the engine kill and see a distinct Reduction in headlight brightness.

    It is not a very scientific test, but it does show me the charging voltage at idle is higher than my static battery voltage and my alternator output is ABOVE nominal battery voltage. Does your bike do this.

    Blink once for No, and twice for Yes. (pm me)
     
  7. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Ahh...Hoop, ya got good ol' fashion observation technique. The headlight trick brightness trick...is a very good one and also one of my troubleshooting techniques when on the road, or helping a fellow motorcyclist or cager on the side of the road. It is also handy not only for the charging system, but also the starting system, using sound logic (listening to the starter activity) while looking at the brightness of the headlight to figure out things out without tools; we have 5 senses, the 6th sense is that logical "feeling", a conflict of terms to be sure, but one that works nonetheless...:s
     
  8. Hoople

    Hoople Account Removed

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    NewHD... It's kind of like licking a 9 volt battery with your tongue to see if it is fresh! I am SURE you have done that!

    Hoop!
     
  9. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    Hoop...your scaring me...!:small3d031:
     
  10. sandmar

    sandmar Active Member

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    Nice tip Hoople,I will remember this.