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battery or alternator?

Coachman124's Avatar

Join Date: Aug 2000
Posts: 124

08-08-03, 07:22 AM   #1  
battery or alternator?

I have a 1994 GMC Jimmy, last night the battery indicator was flashing and the bars on the voltage were low. I shut off the truck, measured the voltage on the battery and only got 5.95 volts, when i started it, it went up to 12.1 volts. I always thought the ideal voltage while the motor was running was around 13.5-14 volts. Can it be staying at 12 volts while the motor is running because of a bad battery or do you think something is wrong with the charging system?

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Joe_F's Avatar
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08-08-03, 07:36 AM   #2  
Sounds like a finished alternator to me. Get an AC Delco rebuilt from the parts store.

If the battery is four years old or more, pitch it for a new Delco too.

sdsdogg2's Avatar

Join Date: Jun 2003
Posts: 47

08-08-03, 02:26 PM   #3  
I really doubt that 5.95 volts will start the engine. Was your meter set to AC volts? If so than your 12 v check was off. If I am wrong than the alt. is generating 6 volts as back to the battery and still running all other accesories Sounds like the alt is ok and a bad battery to me.

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