Dead battery or alternator?????????

Discussion in 'The Okie Corral' started by JAY-TX, Feb 8, 2010.

  1. JAY-TX

    JAY-TX

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    Yesterday my battery warning light came on, on the way home from work. The volt guage was reading in the normal range, but it was on the low end. Whenever the rpm got over 2500 the light would go out. As soon as they dropped back below 2500 rpm it would come back on. The headlights seemed a little dim as well.
    On the way to work this morning, the battery light was still on, and after a couple of miles the voltage gauge went to zero. I returned home and took the other car to work instead. About an hour later my wife calls and tells me the truck won't start. [ 7.3 powerstroke]

    Any of you guys in the wonderful world of GT know which one it might be? Which one should I check first?:faint:
     
  2. Camper10

    Camper10

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    They'll find it
     

  3. metro273

    metro273 Glock 19 Rocks!

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    Sure sounds like an alternator to me! :supergrin:
     
  4. fyrecrotch

    fyrecrotch

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    It's a hell of a lot easier to pull a battery to test it than the alternator. Check the terminals for corrosion/bad connection.
     
  5. IndyGunFreak

    IndyGunFreak

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    I'm not much of a mechanic, but I agree...

    IGF
     
  6. robin303

    robin303 Helicopter Nut

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    Easy my friend, just start the car and then diconnect your battery and if it dies out you know it is the alt. Two bolts and Auto Zone and maybe $100 or less and 30 min later you be good to go. Another way to tell is turn on your head lights when the car is running and if they dim it is still your alt.
     
  7. Mr King

    Mr King XD40 Service

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  8. 220-9er

    220-9er

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    My money's on the alternator but check all the connections and the ground first. Solenoid wouldn't keep it from charging, only starting.
     
  9. JAY-TX

    JAY-TX

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    Fantastic!

    Thanks fellas. I swear, GT is like having an extra hand or something sometimes. :supergrin:
     
  10. Gareth68

    Gareth68

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    DO NOT DO THIS!!!!

    It will damage many modern electronics systems.
     
  11. beatcop

    beatcop

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    As others have stated, clean all terminals w/sandpaper. Borrow a multimeter, turn on engine and all lights, fans, etc....measure voltage between battery terminals. Should be 12.5-13.5 volts or a bit more while under load.

    It's an indicator of alternator condition without using an ammeter. The theory is that you need more than 12 volts coming into the battery to keep a charge.
     
  12. harleyfx69

    harleyfx69

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    not to mention an alternator for a powerstroke will be more than 100 bucks,
     
  13. harleyfx69

    harleyfx69

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    and its not voltage that charges the battery its the amp current from the alternator
     
  14. Scared_of_zombies

    Scared_of_zombies

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    check the water level in your battery, if applicable.
     
  15. byf43

    byf43 NRA Patron Life Member

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    Agreed.

    Do NOT start the vehicle and disconnect the battery!
    This will certainly fry the diodes (at minimum), and possibly do damage to other electronic components. (ECM. . . I'm not sure. Possibly.)

    Safe bet. Take the battery out and get it checked.
    Winter has a way of killing a battery. Replacing the battery will be the easiest and least expensive route, to start with.
     
  16. rustypigeon

    rustypigeon

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    Alternator. 99.99837865774% certain. +/- .000001326%.
     
  17. Danimal3805

    Danimal3805

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    LMAO best one yet!:rofl:

    Agreed

    <-----------ASE L1 Master Tech
    :whistling:
     
  18. Mungrol

    Mungrol Wanabe Like RTN

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    Agree and add my .000000000999999999%
     
  19. GlocknSpiehl

    GlocknSpiehl NRA Life Member

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    I had this problem several times with different vehicles. Always start with the simplest/cheapest fix and then work your way up. In this case pick up a terminal cleaner on your way home and thoroughly clean both terminals, as well as the cable connectors. Inspect the cable connections as well to make sure they are still good and that you have no loose grounds.

    Next check the battery by taking it in for testing. Last thing is check the alternator.
     
  20. hvnit2gd

    hvnit2gd

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    Take it too an auto parts store, they will be able to test the battery and the alternator while they are on the vehicle... the readings will tell them how much battery life you have left and/or which part of the alternator is failing...

    whatever you do, DO NOT disconnect the battery while the vehicle is running!!!