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Hyundai- battery runs down while I drive

First, while driving, my radio dies, my lights start to dim, and I lose my power steering. The first local shop I took it to installed a new alternator and I drove it home. Died again while I was driving. They then replaced three alternators with same results thinking they were bad. Ended up refunding my $400 and putting my original alternator back in and I had my car towed to the Hyundai dealer.

They had car for four days while testing it after charging the battery. They could find nothing wrong with it(again, no charge). Picked it up and drove it home(with someone following me). Two day latter, dead again. What is draining my battery? Do I have a short or something? Thank you for any consideration to my problem.
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Comments

  • Has anyone tried replacing the serpentine belt?

    Tester
  • No one has mentioned it. I don't know what that is or does.
  • You almost certainly have an issue with the serpentine belt or something directly connected to it, as that's the only common link between your charging system and your power steering system. Most likely the belt is worn out or your tensioner isn't making the belt tight enough. Do you ever hear any squealing noises, especially on wet days? It's hard to believe two different shops would overlook this, though.
  • Lino this may not be right, what year is this car?? The newer elantras have electric power steering, 07 and up I think. Maybe 08??


  • GS--No, I think that the serpentine belt (or--more likely--a belt tensioner) is still the common link here.
    Even if the this car has electric power steering, a loose serpentine belt will inevitably cause steering problems.

    In fact, a car with electrically-assisted power steering will probably drain a weak batter faster than a car with the more conventional hydraulic power steering. Insufficient electric power=loss of all electrically-powered accessories at some point.
  • edited February 2012
    I'd be more suspicious of an intermittant open or high-resistance short to ground, maybe even internal to the battery. I'd want to start by removing, cleaning, and reinstalling all the main connections, including the ground strap, and checking the battery terminals for looseness. Depending on the year of the car (I wish we knew), I might even change the battery out even if it tests good.

    The other possibility would be that something is intermittantly creating a high resistance short to ground while the car is operating. Removing the fuses for all unnecessary circuits, and if that stops the problem replacing them one by one, might help find it, but it'd be a crapshoot.

    Another option would be to hook an event recorder up to the charging ciiruit. It's possible that the intermittant is internal to the alternator.

    By the way, OP, have you had an aftermarket audio system or security system installed? Or installed one yourself? Aftermarket lighting, or anything like that?
  • You may have an external voltage regulator, if you do that could be the problem. Even worse, if your car is new enough to have the electric steering, it might also be using the computer to control the charging of your battery. If so, it could be a loose connection at the computer or, if you are lucky, the dealer might be able to fix it by flashing the computer (re-installing the computer program that operates your car).
  • Well, my guess ( which no one believes any way), is that the belt is slipping. That would let the battery go down. And if the power steering is electrical or belt driven, it would fail.


  • Elly--Re-read my response, about 3 above yours.
    While we both could be wrong, I also think that the belt or the tensioner is likely to be the source of the problem.
  • I say don't give up on the alternator. The fourth one might do the trick. Definitely keep going back to this mechanic.
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