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Electrical Advice needed!

Discussion in 'Technical Q&A' started by billwilletts, Jul 14, 2025 at 11:01 AM.

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  1. billwilletts

    billwilletts Rookie

    Jun 7, 2025
    20
    Kenosha and Myrtle Beach
    Full Name:
    William Willetts
    #1 billwilletts, Jul 14, 2025 at 11:01 AM
    Last edited: Jul 14, 2025 at 11:14 AM
    F360 Technical issue.... I went to start my car yesterday and it had been off the trickle charger for a few days, click off the immobilizer, turn the key, car shows N and got the OK light - turn the key and nothing. No clicking or anything. Also noticed the F1 pump doesn't kick on when I open the door. Is it possible to have enough voltage for everything to work but not engage the engine or F1 pump? I put the trickle charger back on for 24 hours now and still nothing. Was thinking about putting a battery box on it to see if it comes to life. And advice would be appreciated.
     
  2. fatbillybob

    fatbillybob Two Time F1 World Champ
    Consultant Owner

    Aug 10, 2002
    28,947
    socal
    #2 fatbillybob, Jul 14, 2025 at 12:05 PM
    trickle charger use destroys a lot of good batteries. I would put a charger on battery disconnected from car then see if it holds charge. If no then get new battery. Do not jump these cars you can end up with airbag lights etc. Ferraris do not have robust electrical systems
     
  3. billwilletts

    billwilletts Rookie

    Jun 7, 2025
    20
    Kenosha and Myrtle Beach
    Full Name:
    William Willetts
    #3 billwilletts, Jul 14, 2025 at 2:12 PM
    That was it.... low voltage. I guess the built in safety is a good thing. No idea why it would have dropped below 12v in just a few days. I turned off the battery switch, with the battery pack off I connected it to the battery terminals, turned the battery pack on, then turned on the battery switch and everything came online. Charged on the alternator in just a few minutes.
     
    Willl and Qavion like this.
  4. Phelips

    Phelips Karting

    May 30, 2025
    60
    Full Name:
    Russel Phelips Brown
    #4 Phelips, Jul 14, 2025 at 9:26 PM
    Weak battery or bad connection even if dash lights work, the starter needs strong voltage. Try a jump box directly to the battery. If it cranks, replace the battery. If not, check grounds, starter relay, and ignition switch. F1 pump not priming points to voltage drop test battery under load.
     
  5. Alden

    Alden F1 Rookie
    Rossa Subscribed

    Apr 25, 2010
    3,596
    Central Florida
    #5 Alden, Jul 15, 2025 at 3:36 PM
    Alternators are not designed to charge a dead battery, you could damage both the battery and the alternator. Take it out, put it on a proper charger and reinstall it.
    If your battery we went completely dead. It's probably toast anyway.
    Alden
     
  6. raemin

    raemin Formula 3

    Jan 16, 2007
    2,337
    Lyon (FR)
    Full Name:
    R. Emin
    #6 raemin, Jul 15, 2025 at 4:14 PM
    The alrernator does provide 5 to 10 times more amps than most chargers, so under certain circumstances this could revive batteries plagged by dendrite. On the other hand if the lead plates are already crumbling, the amperage boost may cause a total failure of the battery, or worst a short.
     
  7. Alden

    Alden F1 Rookie
    Rossa Subscribed

    Apr 25, 2010
    3,596
    Central Florida
    #7 Alden, Jul 15, 2025 at 6:13 PM
    I was just saying that the alternator is not designed to provide sufficient amps to charge a dead battery AND run the systems in the car without stressing it out. Just because it CAN do it doesn't mean it won't harm it.
    Sometimes in these cases you end up replacing the battery and the alternator because both are shot now.
    Easier to remove the battery and charge it or simply install a new battery since fully discharged batteries are usually done for soon anyway.
    Alden
     
  8. raemin

    raemin Formula 3

    Jan 16, 2007
    2,337
    Lyon (FR)
    Full Name:
    R. Emin
    #8 raemin, Jul 16, 2025 at 1:20 AM
    If the battery has been fully discharged its internal resistance is quite high, which means that the amp-draw will be much lower than from a fresh battery (the voltage regulator adjusts the output).

    As said it's when there is a short that a problem could occur: if one of the internal battery cell is faulty, the voltage will be too low and the regulator will increase the output in order to raise the voltage (till destruction if you floor the gas pedal). So it's better to keep the engine idling fo a while (alternator in this case cannot deliver too much amps), and check that the battery voltage is back to normal. If the battery is back to >12v, I keep it.
     

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