1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Why does my battery keep on dying?

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Old 05-06-08, 12:28 AM
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Why does my battery keep on dying?

Replaced old alt with a new one about a month ago.

Ever since, I've been through 3 new batteries and 2 charges...ideas plz?
Old 05-06-08, 12:34 AM
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Probably a drain somewhere?
Old 05-06-08, 12:44 AM
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What drains voltage out of batteries?
Old 05-06-08, 04:19 AM
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Sounds like a short in the alternator.
Had my brandnew 100Amp battry drained overnight that way - took me a while to figure out.
Old 05-06-08, 04:25 AM
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Is the alt hot to the touch?
Old 05-06-08, 04:38 AM
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Start by confirming whether or not the alternator is entering charge mode. Should be reading about 14 volts when engine is running.
Old 05-06-08, 08:06 AM
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It really is not that unusual for an alternator to drain a battery. I seen it several times. Its normally a drop of soldier that the culprit, however, the amps and volts are putting out what they need to to read good. disconnect the alt for the given amount of time that it takes to drain the battery, or go exchange it for another one if they'll let you. They probably wont want to, but be nice to them and they might. Most people would not want the hot battery wire dangling in a hot car, I wouldn't, but then I would change it with another alt I have laying around wheather it was any good or not. I just want to see if the new alt is pulling a draw or not. Some draws are so small that it takes time pull a battery down and then some will go quickly. If you cannot use conventional methods to detect the draw, go the hillbilly way. Replace it and see.
Old 05-06-08, 02:07 PM
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Originally Posted by Jeff20B
Is the alt hot to the touch?
Not sure. I'll check up on my alt.

How do I make sure my alternator is charging properly?
Old 05-06-08, 02:10 PM
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Originally Posted by eatmyclutch
Not sure. I'll check up on my alt.

How do I make sure my alternator is charging properly?
Take the alternator out and bring it to a local car parts store to get it tested.
Old 05-06-08, 02:16 PM
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Or, if you have a volt meter, check the voltage across the battery posts while running. If anywhere around 14 volts shows, you're alt is charging.
Old 05-06-08, 02:30 PM
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I just checked the alt, it read 11.78...

Could I have installed the alt, incorrectly? Everything seems to be plugged in the proper places.
Old 05-06-08, 03:17 PM
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Originally Posted by eatmyclutch
I just checked the alt, it read 11.78...

Could I have installed the alt, incorrectly? Everything seems to be plugged in the proper places.
Thats battery voltage only. Your alt is cooked, toast, veggie juice, finished, kaput. If its new or still under warranty, you'll need to take it back and exchange it.
Old 05-06-08, 05:39 PM
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Easy way to see if the Alternator is charging a usefull current, is to unbolt and remove the positive lead on the battery with the engine running. If the motor dies out, the alt. is shot.
Old 05-07-08, 10:22 AM
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Could be a bad alternator, in particular defective diodes in the alternator. One of the reasons I don't trust rebuilds.
Old 05-07-08, 09:37 PM
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Turned out to be the alternator. Hopefully the replacement will do me better. Thanx for the help.
Old 05-07-08, 09:48 PM
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bring it back and tell them you want a FC alternator for higher amps. I'll install it for you but bring a 12pack of heine
Old 05-07-08, 10:48 PM
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Too late.
Old 05-07-08, 11:42 PM
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Check the amp in your alt, maybe is too low for your car.
Should be reading 13- 14 when your car is running...
Old 05-08-08, 12:12 AM
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Originally Posted by eatmyclutch
Too late.
bullshit. you just started a thread in the west forum "FB VS FC alternator." got ya thinking eyhhh
Old 05-08-08, 12:25 AM
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Doesn't mean I haven't installed it yet...
Old 05-08-08, 04:01 AM
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Originally Posted by paqueras
Check the VOLTS in your alt, maybe is too low for your car.
Should be reading 13- 14 when your car is running...
Correcticated
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