Car Alternator or Battery Issue

Discussion in 'Car Talk' started by Mitevo7, Feb 8, 2019.

  1. Mitevo7

    Mitevo7 Senior Member
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    Dear All,

    I have a car with 1JZ VVTI engine having consistent battery die on me issue. Symptoms i've detected so far:

    1.) Power windows auto mode not working, unless i rev the engine to 2000 rpm
    2.) Power windows roll up too damn slow
    3.) Idling seems very low and at the point of stalling, when the rev gets about 400 rpm, the battery light turned on
    4.) Lights were dimming but it was fixed after i replaced with a new battery (2 weeks old)

    The alternator was fixed a week after replacing with a new battery, by replacing the carbon brushes due to its age. The engine starts and runs fine, however the power windows are still working slow. Idling still pretty lousy, at 650 rpm at cold start, but runs fine after warmed up.

    One fine day, the battery died on me again, but partly due to the car is in a garage under going cosmetic repairs, the repair guy accidentally left the car lights on overnight. The next day we jump started the car but i doubt the battery is properly charged.

    So far our test results as below:

    Battery voltage while engine is off: 11.8 v (mechanic commented it is low, as it should be in between 12.2 - 12.5)

    Battery voltage after engine started with no accessories on (radio, lights, A/C): 13.5v (mechanic thought it looks ok)

    Battery voltage with accessories on (radio, lights, A.C): 13.8v (mechanic said it looks ok)

    Honestly i think the alternator still do not produce enough charge or i am just being paranoid.

    What are the chances i need to replace the whole alternator unit ?

    Thanks,
    Ken
     
  2. 6UE5t

    6UE5t Senior Member
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    Your slow power window I think because of the power window motor.
     
  3. vr2turbo

    vr2turbo 5 Year | Silver
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    Maybe changing the carbon not good enough, other parts high resistance.
    My hyundai old alternator also charging at 13.6 to 13.8v. In the morning the kick seems slow.
    My VR have a new alternator installed and charging at 14.5v....lol
     
  4. gunnerzz

    gunnerzz Well-Known Member

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    Just sharing from experience...Good alternator will produce charging V above 14V with no load.

    However this will depend on the idling rpm. at normal 850rpm it will produce that 14V. Below that rpm it wont.

    My ol Pajero power window is having turbo mode. Its slower at idle when aircond on.if i rev a bit it will becomes normal speed.speed different is not significant but u cam notice it.

    Try maintaining 1200 - 1500 rpm and use the power window, if the speed becomes normal then the power window is not getting enough juice during idle. That could be the same reason the auto mode not triggered at low rpm.
     
  5. vr2turbo

    vr2turbo 5 Year | Silver
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    The wiring could have high resistance also, like my two old cars even the starter have added relay......
     
  6. 6UE5t

    6UE5t Senior Member
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    My Mark X when idle gives between 13.7-14.1v, mostly hovering at 14v. The battery itself (Century Ultramax) when engine off is at 12v.
    My son's Swift is higher, idle can reach 14.2-14.4v and the battery itself (Bosch) at 12.2v.
     
  7. sweelt

    sweelt Well-Known Member

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    power windows railing checked and clean ? my wira, idle 13.6V 800-900rpm. Cold start higher rpm show 14V.
     
  8. vr2turbo

    vr2turbo 5 Year | Silver
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    The battery max voltage output is 12.6v, since 1 cell can produce max 2.1v, but working range if not mistaken from 11.8v upwards. Most will show 12 to 12.4v. Other than voltage got to see the current too.
    Alternator charging from 13.5v upwards, best should be 14v and above....
     
  9. Mitevo7

    Mitevo7 Senior Member
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    Not likely, it happened right after the alternator and battery issue.

    Thanks,
    Ken
     
  10. Mitevo7

    Mitevo7 Senior Member
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    Might be got dirty a little as it sit in the garage for about 4 months. But its was working flawlessly before the battery and alternator issues.

    Thanks,
    Ken
     
  11. Mitevo7

    Mitevo7 Senior Member
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    Now my mechanic recommended to charge the battery to its full capacity first. When revving the engine, the V seems normal to him also its putting out 13.8 with loads. We might need to adjust the idling RPM to be higher so the charge can be higher.

    Thanks,
    Ken
     
  12. Izso

    Izso Boooooossst
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    This is your E36? Which alternator you using?
     
  13. vr2turbo

    vr2turbo 5 Year | Silver
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    But the main charge is when you are driving not idling. If park for long time better get those mini charger hook to house AC current....
     
  14. Mitevo7

    Mitevo7 Senior Member
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    E46ci bro, using stock Toyota 1JZVVTI alternator.

    Thanks,
    Ken
     
  15. Mitevo7

    Mitevo7 Senior Member
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    Now we added a voltage regulator that increases the voltage as well as regulating it. The test results are as below:

    1.) Full Load with accessories on at 2000 RPM (simulate driving conditions) - 14.4 V
    2.) Idling with accessories on (A/C, headlights, Radio) - 13.2 (700 rpm)
    3.) Iding with every accessories off - 14.6 V

    What you guys think ?

    Thanks,
    Ken
     
  16. ^pomen_GTR^

    ^pomen_GTR^ Senior Member
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    obviously after alternator repair the charging is fine...

    your battery if new (and just only accidentally drained once) should be fine...


    as your idle speed, its tuning issue...

    and slow moving power window...is electrical issue..like grounding/wiring is old and worn
     
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  17. Mitevo7

    Mitevo7 Senior Member
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    As for idle speed, since mine is a converted E46 that still uses old 318ci tachnometer, i think the readings will not be 100% accurate. My best guesstimation, when 650 rpm on the tacho, i should have around 700 rpm. The tuner said he can't do it any higher, or else the engine itself will rev itself to 2000 rpm when we apply and release the throttle before going back to below 1k rpm.

    Another findings, when the cooling fan kicked in, the voltage will drop from 13.3 v to 12.7 v, the reading was taken when the car is stationary, to simulate traffic jammes or other bumper to bumper traffic.

    Slow moving power window, i might want to look into the railings. Might just dirty tracks, cause all the groundings are revamped.

    Thanks,
    Ken
     
  18. ^pomen_GTR^

    ^pomen_GTR^ Senior Member
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    if u got like functional obd2 to display (or verify) actual engine rpm...the idle rpm should need no worry...

    but if voltage drop from 13.3 to 12.7 (consistently dropping below 13v),
    do same test... now with ac on, and full headlights on as well on idle.... to see if there is idle compensation during load or not... (not sure if jz have that function or the ecu function) and see if the voltage drop further means alternator amperage not sufficient...


    your radiator fan use jz fan or bm fan?
     
  19. vr2turbo

    vr2turbo 5 Year | Silver
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    Yup, agree with bro. pomen. If voltage drop below 13v then you battery not enough charge already.....
     
  20. Mitevo7

    Mitevo7 Senior Member
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    I am using BMW fan from M43B19, its supposed to be high speed fan. The voltage dropped to 12.7 when the fan is spinning very fast for few seconds, and voltage recover back to 13.3 - 13.4 v after it slow down.

    Thanks,
    Ken
     
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