Alternator light | Page 2 | FerrariChat

Alternator light

Discussion in 'Boxers/TR/M' started by ferralc, Feb 22, 2019.

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  1. 302Tim

    302Tim Formula 3

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    #26 302Tim, Feb 23, 2019
    Last edited: Feb 23, 2019
    Your alternator is always running when the engine is operating--it's directly connected (via belt) to the crankshaft. More accurate is that perhaps your alternator is not producing voltage upon cold start...but it's running. My car sometimes behaves like yours--with no throttle at cold start the light will come on and stay until I either 1) I blip the throttle, or 2) let the engine run until closed loop and the RPM self-adjusts. On mine the light never comes on after a warm start. It's strictly a cold start RPM thing. I've had the alternator rebuilt by a reputable shop and while better (does this less often) it still occasionally does. If you search you'll find others experience this as well. BTW the TR engine tone does change once running in closed loop and makes a more pronounced whistling sound but that's not the sound of a belt running that wasn't before.

    All that said, 12.8V at idle is too low (even though the light is out). Ignore your radar detector readings and as mentioned, measure directly across your battery terminals. At closed-loop idle (RPM=~1K) my battery voltage reads 14.06 or > for a while (to recharge the battery) then settles down to maybe 13.5V to maintain. I sure wish my odometer read what yours does....
     
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  2. ferralc

    ferralc Formula 3
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    #27 ferralc, Feb 23, 2019
    I actually drove the car out of the underground parking garage and the light stay on for a while and then it went off so that is why I assumed the higher RPMS didn’t have any impact on the light, but this morning I actually gave it a little gas while idling and it went off.
    I don’t think it is the wheel because in that case it will happen at every idle, my guess is somehow the alternator belt is not running or something maybe with the voltage regulator?
    well I already told the dealership the car isn’t fixed and I will bring it back for inspection. I will keep you posted


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  3. ferralc

    ferralc Formula 3
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    #28 ferralc, Feb 23, 2019
    This is exactly what is going on!!! Wow exactly what you said!!
    But why I didn’t have that happening with my old alternator??
    But the voltage went up once the alternator started working properly look at the voltage of the first video but as you said the alternator is workings cold start but not producing enough juice for the light to go off


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  4. turbo-joe

    turbo-joe F1 Veteran

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    #29 turbo-joe, Feb 23, 2019
    as long as you have warranty try to get this problem fixed. so as it is now it will be not ok.

    on other cars I had such a problem also when I changed the alternators but then I always put it out again and got a new alternator from my supplier. but this problem has been always after starting, never when the engine only have been cold.
     
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  5. ferralc

    ferralc Formula 3
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    #30 ferralc, Feb 23, 2019
    Yes I will, I started the thread because I wanted to pinpoint the problem first before the dealer blames the wiring or the light itself. It is pretty clear the alternator isn’t working properly because the light is on, the voltage is low and even the dash lights are dim. As soon as I give it a little gas the light went off, the dash lights became brighter and the voltage increased.
    That particular change of sound made me think it was the belt that runs the alternator but just like 302tim mentioned maybe it is just the change of tone of the closed loop. Regardless the car is going back to the shop because it is not properly fixed.


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  6. turbo-joe

    turbo-joe F1 Veteran

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    #31 turbo-joe, Feb 24, 2019
    wish you good luck and please keep us updated
     
  7. ferralc

    ferralc Formula 3
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    #32 ferralc, Feb 25, 2019
    Tim I checked today and you are correct the alternator is spinning but not producing voltage at coldstart.
    I blipped the throttle and the warning light went off, voltage started increasing and that whistling sound started, my question to you is if this is the sound of closed loop can you get closed loop immediately after a coldstart just by blipping the throttle?
    I thought closed loop needed a bit of time for the RPMS to settle, I blipped the throttle within 5 seconds and everything started working correctly.

    My voltage at my radar detector went to 13.5v max and then normalized down to a range of 12.8-13.1.
    A more accurate reading at the terminals might show a bit more but at least it behaves as expected.
    I could live with this coldstart issue by just blipping the throttle at every coldstart but the car did not behave like that and I will take it back to the dealer in a couple of weeks (they are always saturated)





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  8. turbo-joe

    turbo-joe F1 Veteran

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    #33 turbo-joe, Feb 25, 2019
    such "whistling" you normaly can hear when the battery is down and the alternator has to work full power to charge the battery or when the alternator is not working right ( in your case ). you may check the power also with an amp-meter, switch on all electric consumers and see how many amp the alternator delivers. also during this test you activate the power windows. if you not have an amp-meter then do the same procedure and look at the voltage meter. may not go down under 12.8 V with minimum 1800 rpm. also listen to the whistling if it will get louder.
    but nevertheless it makes no sense to discuss this here because the alternator is not working right and you still habe warranty. so you know what to do ;)
     
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  9. ago car nut

    ago car nut F1 Veteran
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    #34 ago car nut, Feb 26, 2019
    Whistling sometimes means bad diodes.
     
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  10. ferralc

    ferralc Formula 3
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    #35 ferralc, Feb 26, 2019
    The car is going back for sure, but because I do have a couple of weeks until then I am wondering what could be the cause? Bad alternator?, slow idle?, bad connection?
    Thanks Joe


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  11. ferralc

    ferralc Formula 3
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    #36 ferralc, Mar 8, 2019
    Last edited: Mar 8, 2019
    I just took my TR to a second opinion and he told me that is the way that car is supposed to work. That around 89 Ferrari changed the resistance (or something) and the lights go off as soon as the car starts, but when they were new the lights stay on until the car reached around 1500 rpms.
    He told me that very few TRs still work that way because the alternators have been rebuilt.
    And yes the radar detector voltage was not accurate either.
    So I am good now!!!


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  12. turbo-joe

    turbo-joe F1 Veteran

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    #37 turbo-joe, Mar 8, 2019
    this is totally new for me and it is hard for me to believe.
     
  13. ferralc

    ferralc Formula 3
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    #38 ferralc, Mar 8, 2019
    I am skeptical too, I will still bring the car back to the dealer to see what they say but that is what this other mechanic said (another shop)
    It was the regulator not the resistance what I meant in my previous post btw

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  14. 302Tim

    302Tim Formula 3

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    #39 302Tim, Mar 9, 2019
    Can't be true (no manufacturer would design a system that purposely illuminates a red light on the dash with the engine running (and electrical system running nominally) on purpose--owners would freak). but regardless, if you are gettting sufficient charging voltage at the battery and the light goes out after a quick rev then I'd say you are GTG. I'm very finicky about my car but the light on only for a few seconds at cold-start idle...I've gotten over it. Out of curiosity what voltage are you reading at the battery at idle? Best of luck with your car.
     
  15. turbo-joe

    turbo-joe F1 Veteran

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    #40 turbo-joe, Mar 9, 2019
    what is GTG?
     
  16. Natkingcolebasket69

    Natkingcolebasket69 F1 World Champ

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    #41 Natkingcolebasket69, Mar 9, 2019
    Good to go;)


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  17. Motob

    Motob Formula 3
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    #42 Motob, Mar 9, 2019
    Last edited: Mar 9, 2019
    Why did you have the alternator replaced? The original Ferrari TR alternator is made by Delco, which can easily be rebuilt by any competent alternator rebuilder.
    It is pretty typical for some alternators to not start charging unless you get the engine RPMs above 1500 RPM. The charging light on a 308/328 will never go out unless you blip the throttle. Will the light go out if you raise the engine RPM right after starting? My guess is that the new alternator has a different voltage regulator from the original, and needs to have some RPM for it to start charging.
     
  18. ferralc

    ferralc Formula 3
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    #43 ferralc, Mar 9, 2019
    Exactly everything you said
    The mechanic mentioned exactly that newer alternators have regulators that begin energizing at lower roms and that is normal to happen. And years ago alternators needed more rpms to start.


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  19. ferralc

    ferralc Formula 3
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    #44 ferralc, Mar 11, 2019
    Another video I found behaving just like mine (but at even higher rpms), I have heard this happens pretty often, maybe not the norm but close.



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  20. Drew Altemara

    Drew Altemara Formula 3

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    #45 Drew Altemara, Mar 11, 2019
    Are you sure the belt is not slipping?
     
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