Alt. Light

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Feb 4, 2005 | 01:06 AM

minishtr

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Alt. Light

If my Alt. is overcharging my battery will me Alt. light come on? I think it's overcharging because,when I installed the new battery it read 12.5 volts and now after running it awhile it reads 13.5 volts.

Brian

Feb 4, 2005 | 05:42 AM

trike1946

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From: NJ where fun comes to die

How much is it charging at idle? And then rev it up and see how much it is charging at 1500 - 2000. Don't go by the dash gauges, use a meter. What vehicle is it?

Feb 4, 2005 | 01:50 PM

jtmerritt

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Surprisingly 12.5 volts is considered low voltage for a battery. In a good state of charge the battery should show about 13 volts. As trike1946 siad you really need to use a meter to measure charging voltage. Don't be surprised if you see 14 volts at times when charging. Your alternator light won't come on unless the voltage at the battery is less than 12 volts. Higher voltages won't make it come on.

John

Feb 4, 2005 | 11:57 PM

minishtr

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It's a 64 F100 with a 223 and a GM one wire conversion.Here's what it does at start up alt. light comes on bright,rev it up light goes very dim almost can't see it.Using a meter at the battery it reads 14.44 volts at idle and higher revs.Any ideas?Checked all wiring all seems good.

Brian

Feb 5, 2005 | 05:12 AM

trike1946

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From: NJ where fun comes to die

I'm not familiar with the one wire conversion. Do you have an external regulator? My vehicles go from 13.5 to 14.5 at start up. The alternator produces the power and the regulator limits the amount of power going back to the battery. What condition is your battery in?

Feb 5, 2005 | 10:49 PM

Franklin2

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Once you rev it up, and the alt light goes dim, does it stay dim until you turn the truck off? If so, that is normal for a one-wire alternator with a self-exciting regulator.

Feb 5, 2005 | 11:25 PM

minishtr

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That is what it's doing.I did not notice it when I first did the conversion but I had an old deep cycle/starting marine battery in it that died on me.Guess I'll drive it awhile and see if it's working OK.

Brian