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S4 battery light on, but showing 15 volts!

Discussion in 'A4/S4 forum(B5 Chassis)' started by Geeman, Sep 9, 2011.

  1. Geeman
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    Geeman Low Life

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    [Sep 9, 2011]
    So, I played with the S4 a bit last night... by changing the wiper motor and mechanism out for a quiet one (God, was the old one noisy!) and adding some aero wiper arms and blades from a late model B5.5 Passat.

    In the process of replacing the wiper mechanism, I had to take the lid off the ECU box and unbolt it to move it out the way so that I could get the mechanism out.

    I went to the car this morning and the battery light was on. When I rev the car, the volts on the dash go up from 12 to 14/15 and then stay there. The mileage counter doesn't seem to be adding the miles on either. Also, my 'miles left' figures aren't working either. Sometimes it reads 00, then it'll read 75... even thought there's still 3/4 of a tank of fuel in there.

    I'm thinking I might have disturbed something within the ECU box.

    Any ideas?
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  3. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    [Sep 9, 2011]
    The volt meter should go to 14.5 volts as soon as the car is started.
    #2
  4. Geeman
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    Geeman Low Life

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    [Sep 9, 2011]
    Okay... but what about the battery light and the other problems?

    They all started at the same time this morning.
    #3
  5. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    [Sep 9, 2011]
    Try disconnecting the battery hold both terminals together for 10 seconds then if faults is still there the I'd be checking what you have disconnected and the wiring running through the ecu box make sure you haven't crimped one by mistake and check the actual out put that the alternator is kicking out to rule out the alternator.
    #4
  6. Geeman
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    Geeman Low Life

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    [Sep 9, 2011]
    [​IMG]
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  7. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    [Sep 9, 2011]
    I'd say that's about right as mine sits around there. Will double check though.
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  8. Geeman
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    Geeman Low Life

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    [Sep 9, 2011]
    Maybe it's just me being paranoid. I've never really noticed it before... but with the battery warning light coming on, it's the first thing I looked at!
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  9. Bradderz_1988
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    Bradderz_1988 Dont replace it, Upgrade it !!

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    [Sep 9, 2011]
    Is it in whilst driving ??
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  10. Geeman
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    Geeman Low Life

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    [Sep 9, 2011]
    Yeah... it's on all the time.
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