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Voltmeter staying at 12v till reved?

Discussion in 'A4/S4 forum(B5 Chassis)' started by griswold, Jan 30, 2011.

  1. griswold
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    griswold Member

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    [Jan 30, 2011]
    On the wifes A6 2.4 when starting the voltmeter shows 12v at idle but if you rev it a little it finally goes to 14+ but my A4 1.8 instantly goes to 14+
    Is this normal for the v6 engine?
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  3. adamss24
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    adamss24 Well-Known Member

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    [Jan 30, 2011]
    Put a multimeter on the battery whilst the engine's running. It should be a steady 14.4 Volts. Less or more not good...
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  4. griswold
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    griswold Member

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    [Jan 30, 2011]
    Its a new battery and been on the car a few months with no problems but it was doing it on the old one too
    its just on the initial startup it goes to 12v but unless revved a liitle or driven it wont go to 14v straight away
    I'm sure its getting 14+v when the gauge shows it otherwise im sure i would have had a flat battery by now.
    I will check later when she gets back what voltage its getting when sat at 12 and at 14
    surely it whould go there straight away?
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  5. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jan 30, 2011]
    It could be a dodgy connection on the D+ or "warning light" wire. Does the battery light come on with the ignition then go off once started?
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  6. griswold
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    griswold Member

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    [Jan 30, 2011]
    Ok i put a multimeter on the battery after starting was showing 11.64volts give it a rev and went to 14.10 volts but the heater was on so maybe that took a little thought it would be 14.4v

    There was no battery light before starting or when running ?
    just engine light abs handbrake and airbag light if memory right?
    vag com clear
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  7. aragorn
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    aragorn "Stick a V8 in it!" Staff Member Moderator VCDS Map User

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    [Jan 30, 2011]
    14.1 is normal. 14.4 is a bit on the high side for a cars charging system.

    Remove the small wire from the alternator, and check for battery voltage at the wire with the ignition on.
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  8. Broken Byzan
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    Broken Byzan Photographic Moderator Staff Member Moderator VCDS Map User

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    [Jan 30, 2011]
    More likely a lazy alternator regulator.

    Does it stay at 14 ish once it's been revved up regardless of what's on?
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  9. griswold
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    griswold Member

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    [Jan 30, 2011]
    Just had to change my A4 battery sure that was 14.4 but probably .04 then when i checked that.
    As for checking the alernator not sure if i can get to it easy as its a V6 not much room or time with the car
    Any other ideas guys?
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  10. griswold
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    griswold Member

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    [Jan 30, 2011]
    Yes once revved it doesn't budge from 14v heaters stereo lights all on no problems at all
    can the alternator regulator be relplaced or has it got to be a new alternator?
    thanks Mark
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  11. Broken Byzan
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    Broken Byzan Photographic Moderator Staff Member Moderator VCDS Map User

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    [Jan 30, 2011]
    TBH I wouldn't worry.
    The reg is located within the alternator, usually replaced when reconditioning the alternator as well as the brushes. That is pretty much all there is within the alternator, don't panic
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  12. electricracer
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    electricracer Member

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    [Jan 30, 2011]
    second that i wouldn't worry as long as it rises when its reved. my golf did this for about 5 years never had problems, one thing if you start the car to defrost it dont forget to blip the throttle to start the charging. if you could be bothered replace the regulator but i wouldnt worry
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