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Alternator voltage

Discussion in '2nd Gen. Tacomas (2005-2015)' started by Swwacoma, Aug 3, 2011.

  1. Aug 3, 2011 at 3:35 PM
    #1
    Swwacoma

    Swwacoma [OP] Doomsday Squad

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    Howdy fella's and fellettes.

    Just had the lovely experience of my battery stone cold dying in our cool 102 degree weather we have today, and after waiting for just a short two hours or so for AAA to come and replace my battery the guy told me that my alternator was running at a low 13.9Vs and told me to get my alternator checked out.

    I just want to know what the alternator should be reading. Is 13.9 low? normal? Should I stop typing and got the hell to a dealership?!

    I'm poor at search so I apologize if this was discussed and I missed it. Just point me in the right direction if so.
     
  2. Aug 3, 2011 at 4:02 PM
    #2
    Crom

    Crom Outside

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  3. Aug 3, 2011 at 4:05 PM
    #3
    Swwacoma

    Swwacoma [OP] Doomsday Squad

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    Thanks much, so it looks like I'm fine.
     
  4. Aug 3, 2011 at 8:33 PM
    #4
    Isthatahemi

    Isthatahemi Well-Known Member

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    Mine runs 13.8-13.9. Very annoying for us RV'ers, as this drops to 13.6- 13.7 with the trailer hooked. It does not charge the trailer batteries hardly at all. Very annoying. 14.4 was the norm in every other vehicle I have owned.
     
  5. Aug 3, 2011 at 9:41 PM
    #5
    Swwacoma

    Swwacoma [OP] Doomsday Squad

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    Well that makes me feel better that I'm not the only one. I guess that explains why the guy thought I was so low if we tend to run lower than the norm. I don't ever pull anything, so it sounds like I'll survive.
     
  6. Aug 3, 2011 at 10:02 PM
    #6
    Mr.Tacoma

    Mr.Tacoma Well-Known Member

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    I pulled my travel trailer with elec brakes, smelt some burning..got home otherwise. few days later batt light came..now no signs/lights on dash when i turn key..i am in the process of rebuilding the alt..probably will get it done for 140 or 150 amps.
     
  7. Aug 4, 2011 at 8:19 PM
    #7
    myname150

    myname150 Well-Known Member

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    13.9 Low?

    My SGII is usually telling me 14V when I first start the truck in the morning, after I've been cursing down the highway to school in the mornings, my reading is usually in the upper 13V. Lowest I've seen is 13.5V.
     
  8. Aug 4, 2011 at 9:13 PM
    #8
    Swwacoma

    Swwacoma [OP] Doomsday Squad

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    That's what the guy told me. Figured I'd check with y'all before I got concerned about it. Sounds like he just wasn't familiar with the Tacoma.
     
  9. Aug 4, 2011 at 9:27 PM
    #9
    Yoytoda

    Yoytoda The Little Truck That Could

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    if the battery was dead there will be a greater load so 13.9 sounds perfect
     
  10. Aug 4, 2011 at 11:15 PM
    #10
    JKD

    JKD Well-Known Member

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    Voltage is also going to depend on temperature. Higher temps, lower voltage and vice versa. It's due to lead acid battery chemistry.
     
  11. Aug 5, 2011 at 12:29 PM
    #11
    Swwacoma

    Swwacoma [OP] Doomsday Squad

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    Yeah, it was mid day in South Florida so it wasn't cold. All good advice. Thanks guys. I'd buy you all beers, but yanno . . . just had to buy a new battery.
     
  12. Jan 8, 2014 at 5:36 PM
    #12
    udelslayer

    udelslayer Well-Known Member

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    Is there an index/glossary for those customtacos links?
     
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