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Charging problem back again

Discussion in 'General Chevy & GM Tech Questions' started by BiG Chris, Mar 24, 2011.

  1. BiG Chris

    BiG Chris Member

    Ok this is my old post: Original Thread http://www.gmtruckclub.com/forum/showthread.php?52494-Alternator-issue

    Now heres whats happening now and a little video to show. The lights also still dim a little and fluxuate at idle. PLEASE HELP ME

    http://www.youtube.com/watch?v=UalJb9SSJso
  2. Boneyfingers

    Boneyfingers New Member

    Charging Problems

    Have you looked into the condition of your battery ?

    Another possibility is the battery cables, corrosion at the battery terminal or
    down inside the insulation.
    A loose cable can cause reactions of this type. It makes a high resistance contact
    if it's not tight enough. This applies to both ends of the cable.

    Boneyfingers
    2003 GMC Yukon XL Denali
    1997 Chevy c-3500 CC Dually
    1994 GMC K-1500 Long bed
    1994 Chevy K-5 Blazer
  3. SkullMountainRider

    SkullMountainRider New Member

    Boneyfingers makes some good points. A few Questions that I have are, do you have after market stereo equipment? What amperage is the alternator?
  4. BiG Chris

    BiG Chris Member

    Boneyfingers the battery tested good and I also checked the cables and they seem good there is no corrosion at the terminals. its tight at the battery and at the starter the negatives are tight as well.

    SkullMountainRider there is no aftermarket stereo or anything else to draw current. the replacement alternator is 130amp
  5. SkullMountainRider

    SkullMountainRider New Member

    Hmm.. A 130 amp should give you more than enough power. I'm wondering if you can test the gauge to see if it's operating properly? Or if there is a corroded wire somewhere that's just hanging on.?
  6. Boneyfingers

    Boneyfingers New Member

    Charging Problems

    Chris, Since al the usual things check out it now has you
    checking the small wiring off the alternator ,, the plastic connector that
    puts the voltage to the field windings can have the pins pushed up and
    you won't be able to see it without examining it.
    Also, an alternator has to have a minimum of 8 volts in the battery to
    activate the field windings. There is no magnetism inside the alternator
    without the 8 volts, they do not have permanent magnets.
    Good Luck,
    Boneyfingers
  7. MightyMax

    MightyMax Rockstar 100 Posts

    Man, that issue looks like a corrosion issue to me
    Make sure Battery terminals and wires are clean.....and that the insulation is not worn down anywhere that would allow for the wire to short on the chasis somewhere.

    Get a digital volt meter as well and start checking your voltage readings across the charging circuit. Maybe then you can see if there is a drop occurring at some point in the circuit.
  8. BiG Chris

    BiG Chris Member

    Tonight I will chase down some wires to see what I can find and make sure the grounds are good, also i checked the voltage output at the alternator and it puts out 14.4v and then at the battery it reads 14.0 that was just at idle
  9. MightyMax

    MightyMax Rockstar 100 Posts

    Take the same readings w/ the engine rev'd up some.

    A 0.4v drop seems kinds suspicious to me....
  10. 3e4u

    3e4u New Member

    I just got my 99 Suburban back from the shop yesterday for the exact same issue. I asked the guy who fixed it what he did. He said there was a high amount of resistance between the alternator and the battery. This causes the alternator to work harder and then it will "quit" for a bit and then work fine again. i am guessing the problem gets worse the longer you drive.
    So basically he said he cleaned up the connections between the battery and alternator and got the resistance back down to an acceptable level. It would be good for you to have a ohm meter to check out the readings yourself.
    I messed around under the hood on and off for about a month before I gave up and took it in to be fixed. All seems to be good now.
    Hope that helps.

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