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Alternator issue?

Discussion in 'General Chevy & GM Tech Questions' started by BiG Chris, Oct 10, 2010.

  1. BiG Chris

    BiG Chris New Member

    So tonight on my way home I noticed my light dim a little, so I looked at the volt meter gauge and it was dipping below 14v where it usually sits and when I accelerated more on the freeway it would dim the lights more. I think its a alternator issue, has anyone had this issue before? I think tomorow I am going to pull the alternator out and have it checked at the local parts store.
  2. stephan

    stephan New Member 1000 Posts

    Hey Chris, instead of pulling the alternator off why not drive your rig down to one of the Auto parts stores that check them for free right on the car? That way you will get the battery and all the wireing checked too.
  3. BustedKnuckles

    BustedKnuckles New Member

    I would definitely take the whole rig down to the parts store. Most of the machines that I know of can only check for bad diodes, regulators, and voltage difference. But they can't test for amperage under load. So if the alternator is mostly working, but not able to provide full power under load, these machines can give a false positive that the alternator is good. But the machines they take outside can check for full load, but you need to check all your connections, and belt tension, before hand or you can get a false bad diagnosis. Make sure they check the battery first then the charging system. Its all free, but might as well be done right.
  4. BiG Chris

    BiG Chris New Member

    Alright you guys are right I will just do that, I will let you know the outcome
  5. BiG Chris

    BiG Chris New Member

    Ok so I took truck to the parts store to have the whole system checked and it all checked out ok. I dont know what to do now because after a few hrs I came out of another store hopped in the truck and driving through the parking lot the volt gauge was way under 14v for awhile then it came back up. So now im lost and any advise will be greatly accepted
  6. stephan

    stephan New Member 1000 Posts

    This is beginning to sound like a ground problem Chris. Is this a Surburban?
  7. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member ROTM Winner Platinum Contributor 1000 Posts

    Chris......it might be the Stepper Motor for the Volt/Alt Gauge is going bad.....I'm just taking a guess,as I don't know what year your Truck is??.....:glasses:
  8. BiG Chris

    BiG Chris New Member

    Sorry guys the truck is a 2000 Silverado with the 5.3 z71
  9. 99'HEARTBEAT

    99'HEARTBEAT Moderator Staff Member ROTM Winner Platinum Contributor 1000 Posts


    O.K......What I have mentioned above is most likely the Problem with your Volt/Alt gauge,your Stepper Motor is going out..(Bad)......and would need to be replaced....it is a common problem on these trucks.
  10. BiG Chris

    BiG Chris New Member

    Ok is that in the alternator? or am i being a noob?

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