Bamafan: My Kia's been doing the same since July. Can't get it fixed, had it in the shop four or five times now. By the time the shop gets it, everything's fine. They just had it for a week and found nothing.  Seems like an alternator problem, but that's been replaced and it still did it. Make sure and post if you get it figured out.  Problem is dangerous, especially if it happens at night

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sacoo