Question?

Discussion in '4X4 Truck Talk and Repairs' started by NewMexicoCatfisher, Oct 22, 2009.

  1. NewMexicoCatfisher

    NewMexicoCatfisher New Member

    Messages:
    233
    State:
    Alameda, New Mexico
    Hey all,

    I have a question about my battery light. It comes on when my truck engine is under 2000 rpms, but over that it shuts off. Do you think it could be the alternator?

    Thanks
     
  2. centexcop

    centexcop Well-Known Member

    Messages:
    3,039
    State:
    Texas
    It could be the alternator, or it could be something as simple as a loose or slipping belt.
     

  3. flatheadslayer

    flatheadslayer New Member

    Messages:
    5,834
    State:
    Thomaston, Geor
    mine did that it was the batt.,but it could be your.or your alt. crank it make sure everything turned off pull off terminal if it dies its the alt.
     
  4. fishstick

    fishstick New Member

    Messages:
    1,885
    State:
    Fouke, Arkansas
    or a corroded connection on a battery post. or a weak battery.
     
  5. trnsmsn

    trnsmsn New Member

    Messages:
    1,214
    State:
    Missouri Originally Now I
    If you have a voltmeter, check your voltage @ the time the light is on. You'll probably see that it is near or below 12 volts. If your belt is not loose, as stated earlier, your problem is in the alternator. If you are able to check it @ the back of the alternator, you will eliminate any prolems between it & the battery.

    I recently had to replace mine for the exact same reason. I haven't seen an external regulator in years, so the diagnosis is greatly simplified.

    HTH, Elliot
     
  6. NewMexicoCatfisher

    NewMexicoCatfisher New Member

    Messages:
    233
    State:
    Alameda, New Mexico
    Checked the belt, it wasn't loose. The connections were all fine, and there was no corrosion on the battery. Looks like I'll be needing a new alternator. :sad2:
     
  7. fishstick

    fishstick New Member

    Messages:
    1,885
    State:
    Fouke, Arkansas
    before you change the alternator do this test. with your engine not running, turn on your headlights and leave them on for about 2 to 3 minutes then try and start the engine. if the starter turns fast and starts the engine then the battery is probably ok if the engine turns slowly or wont start the engine then the battery is bad.
     
    Last edited: Oct 22, 2009
  8. trnsmsn

    trnsmsn New Member

    Messages:
    1,214
    State:
    Missouri Originally Now I
    If you are lucky enough to be within close proximity of an AutoZone, they will check the alternator & the battery, while they are still on the vehicle for no $$$.

    Although their intentions are good, you will probably be dealing with a relatively inexperienced youth & It is usually their first response to ask you to "rev" up the engine. Please decline that request & check the system voltage while the battery light is on, as that is most likely the only time the system is @ fault. You would probably be suffering from a dead battery condition if that were not so.

    Good luck & keep us posted....GIT-ER-DONE !!!!!!!!!:wink:
     
  9. NewMexicoCatfisher

    NewMexicoCatfisher New Member

    Messages:
    233
    State:
    Alameda, New Mexico
    Well I went over to the Ford dealership today cause it is the closest auto-shop. They tested the battery, the alternator, and both came out fine. They worked on it for about 45 minutes, just tinkering around I guess and then the light shut off. They didn't even seem to know what caused it. Everything seems good for now...