550 - likelyhood for alternator failure ? | FerrariChat
Buy

550 - likelyhood for alternator failure ?

Discussion in '456/550/575' started by LVP488, Jun 23, 2025 at 6:55 AM.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. LVP488

    LVP488 F1 Veteran

    Jan 21, 2017
    5,818
    France
    #1 LVP488, Jun 23, 2025 at 6:55 AM
    After a timing belts service (which includes the replacement of accessory belts), and only a few km, the generator is not charging the battery anymore.
    The battery alarm is displayed on the dashboard, and by checking the voltage on the battery it's clear that there is no charging.
    The AC is still working, so it's not a belt issue. There is a strange noise; maybe something is loose so that in spite of the belt running the alternator is not turning ?
    The car is 25 years old and has about 27,000 miles - the alternator is probably the original one. Typically the "life expectancy" of an alternator is expressed in km (or mileage), so I wonder how likely it is to need replacement.
     
  2. tazandjan

    tazandjan Three Time F1 World Champ
    Lifetime Rossa Owner

    Jul 19, 2008
    39,119
    Clarksville, Tennessee
    Full Name:
    Terry H Phillips
    #2 tazandjan, Jun 23, 2025 at 4:23 PM
    Check the ground strap first. Common problem.
     
  3. LVP488

    LVP488 F1 Veteran

    Jan 21, 2017
    5,818
    France
    #3 LVP488, Jun 23, 2025 at 4:44 PM
    Thanks :), I will try that.
     
  4. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    28,842
    socal
    #4 fatbillybob, Jun 23, 2025 at 6:24 PM
    install error after major? start by VOM on battery engine running should see min 13.8V-14.5
     
  5. Qavion

    Qavion F1 World Champ
    Silver Subscribed

    Feb 20, 2015
    14,165
    Sydney
    Full Name:
    Ian Riddell
    #5 Qavion, Jun 23, 2025 at 8:20 PM
    If the voltage is ok, but the alternator is making noises, it seems prudent to have an expert check the bearings.
     
  6. LVP488

    LVP488 F1 Veteran

    Jan 21, 2017
    5,818
    France
    #6 LVP488, Jun 24, 2025 at 9:52 AM
    Voltage drops to less than 12V when engine is running (after having charged the battery with an external charger to put it at 13V), so definitely the alternator is not charging.
     
  7. LVP488

    LVP488 F1 Veteran

    Jan 21, 2017
    5,818
    France
    #7 LVP488, Jun 28, 2025 at 10:55 AM
    The rotor rings are showing bad wear, after cleaning it works again but apparently durability of this fix is not guaranteed... Replacement of the alternator seems safer (that's about $800 all-in, cheap to get some confidence...)
     
  8. Timmo

    Timmo Formula Junior

    Aug 26, 2017
    674
    Continental Europe
    #8 Timmo, Jun 28, 2025 at 11:29 AM
    Do you still have the air duct between the undertray and the lower belt cover?
     

Share This Page