2007 Pontiac Grand Prix Voltage flucuates

2007 PONTIAC GRAND PRIX
75,000 MILES
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RDB5380
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My battery voltage flucuates between 14.4 and 12.6 when driving. The more things I have on like lights or a/c the better it is. I have replaced battery, belts, and alternator which the regulator is connected to. I dont know what else it could be besides a short somewhere. Is there anything you can suggest to figure it out?
Aug 11, 2013 at 5:40 PM
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JACOBANDNICKOLAS
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Do you mean the more electrical load you place on the alternator, the higher the voltage?

If the car is at an idle in neutral and nothing electrical is on, what voltage are you getting?
Aug 11, 2013 at 9:12 PM
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MADMIKE1735
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your alternator will only charge when it sees a need to..... this fluctuation you describe is normal.... it cant always charge the battery, if it did, it would be overcharging it.... thats why when you have your acessorys on, it stays around 14v.... it needs to keep up with the demand.
Sep 14, 2013 at 9:42 PM
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