355 Battery Warning Light Flashes On and Off around 5000 RPM | FerrariChat
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355 Battery Warning Light Flashes On and Off around 5000 RPM

Discussion in 'Technical Q&A' started by bkmberg, Jan 11, 2010.

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  1. bkmberg

    bkmberg Formula Junior

    Jun 14, 2005
    385
    LA
    Full Name:
    Frances
    #1 bkmberg, Jan 11, 2010
    Have a question about what could be the cause for the Battery Warning Light to flash on and off a couple times around 5000 RPM. It doesn't happen every time, but it does happen every now and then when around 5000 RPM. The car sounds and drives just fine. Prior to this recurring Battery Warning Light issue, the car had to be jumped once as it would not start on its own. Ever since that one time it had to be jumped, the warning light issue started. Already replaced the alternator but that didn't stop the warning light issue. Please help. Thanks.
     
  2. TED13B

    TED13B Rookie

    Jan 6, 2006
    5
    #2 TED13B, Jan 11, 2010
    Sounds like the alt belt is slipping.
     
  3. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
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    #3 ernie, Jan 11, 2010
    Yeah, I would check the tension on the alternator belt.
     
  4. bkmberg

    bkmberg Formula Junior

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    #4 bkmberg, Jan 12, 2010
    Thanks for the replies. I'll ask the tech to check into that.
     
  5. ferrarioldman

    ferrarioldman Formula 3
    Professional Ferrari Technician Silver Subscribed

    Jun 19, 2002
    1,032
    Summerfield, NC
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    Tom Jones
    #5 ferrarioldman, Jan 12, 2010
    There is an update on the early 355's to install a ground strap from the alternator to the engine block. May want to check and see if this has been done. Could be having intermitten grounding issues with the alternator.
     
  6. Paul_308

    Paul_308 Formula 3

    Mar 12, 2004
    2,345
    #6 Paul_308, Jan 12, 2010
    Jumping a car and having alternator light come on soon thereafter is the reason not to jump start cars. Jumped incorrectly and you take out one of the alternators 3 diodes. With 1 or 2 blown diodes, the alternator will appear to work but will soon fail completely.

    The method used by AAA or tow companies is to charge the dead car's battery slowly for 10-15 minutes using a separate battery and flimsy cables. Light duty cables limit the current and possible spiking. Then remove the cables and start the car.

    Whatever, don't start the engine in the donor car. That worked when we had generators but not with alternators.

    Since you've learned your lesson and replaced the alternator, I would suspect the new alternator of the flashing light. Methinks some of the Chinese replacment alternator regulators can't handle the higher revs of your car.
     
  7. agnello11

    agnello11 Karting

    May 27, 2008
    79
    #7 agnello11, Jan 13, 2010
    Agreed, I too would suspect the regulator in the alternator - new alternator or not - and would look there first. A slipping belt is highly unlikely, particularly at higher rpm.
     
  8. CaptOharry

    CaptOharry Formula Junior

    Jan 4, 2009
    763
    Green Cove Spgs FL
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    Harry Welch
    #8 CaptOharry, Jan 13, 2010
    Look at the Alternator pulley,does it look as if it's been heating up? Signs of light rust? Then yes I'd say a loose belt.If not look at the brushes and springs which make contact on the armature.In any case remove the Alternator check all connections,open her up you might be surprised at what you find.
     
  9. bkmberg

    bkmberg Formula Junior

    Jun 14, 2005
    385
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    Frances
    #9 bkmberg, Jan 18, 2010
    we've check all of your suggestions above and none of those are the problem...also checked the dash to see if that is the issue and found nothing wrong with that....will go on checking....any other possibilities?
     
  10. ernie

    ernie Two Time F1 World Champ
    Lifetime Rossa Owner

    Nov 19, 2001
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    #10 ernie, Jan 18, 2010
    Last edited: Jan 18, 2010
    Well if the belt is not loose, and the extra ground strap is in place, then I would say your voltage regulator is not up to the task. By chance, does your tachometer act weird when you are at full throttle? You can rebuild it yourself for about $50. Yes you read that correct .....fifty, five, zero, $50 bucks.

    Here's the how-to. http://ferrarichat.com/forum/showthread.php?t=142329

    You may also want to check the condition of the brushes and slip rings while you are at it.
     
  11. bkmberg

    bkmberg Formula Junior

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    Frances
    #11 bkmberg, Jan 19, 2010
    Ok thanks. will try this and let you know what happens.
     

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