Questions and Answers

Alternator Question Q. Just before my alternator went dead it was reading low on the dashboard voltmeter. I replaced it and, since my battery wouldn't hold a charge, I borrowed one from another car. The voltmeter started reading almost off the scale on the high end and would fluctuate with acceleration and deceleration, never dropping below the middle of the scale.

I noticed, however, that my battery was getting hot and hissed, so I bought one recommended for my car. Now the voltmeter reads steadily almost at the low end of the scale and won't change with acceleration or deceleration. It concerns me how low it reads... almost as low as it was before the alternator died. Did I get a bad remanufactured alternator, or what?

Thanks,
David

A. Having three different batteries in the car is a little confusing. Your original battery was just plain shot if it wouldn't hold a charge. This might have been a contributing factor to the death of the original alternator since the car is running off the alternator and not the battery.

As for battery number two, when a battery starts cooking like that, it's usually a sign of overcharging or a shorted battery. The overcharging can be confirmed by the voltmeter.

Now that battery number three is a known good battery, and the alternator is not showing a charge, you might have burned out or gotten a defective alternator.

Since your voltmeter showed an overcharge, we can assume the meter is reading correctly and that the first alternator was indeed bad. I think the best thing to do at this point is to have the charging system completely checked out and confirm the alternator is indeed bad. Usually the place you got the battery from can do this. If not, I would have it checked out at a shop.

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