Alternator

[GambleFury]

Okay i have a 1990 Camaro with a 305. My alternator is charging the battery at 21.5 volts!!! What is the Prolbem? I just installed my 3rd alternator yesterday and the problem keeps happening. I have check both grounds from the battery and they both show a .3 volt drop so they are good where am i suppose to go now. Thanks for any help!

[wrightz28]

Are you ckecking the output with a voltmeter or jsut going off the dash gauge?

[GambleFury]

Vlotmeter it just jumped to 22.8.....i just checked the fuse in side the car and it is good

[wrightz28]

somehting is massively wrong with the battery then, stop running it.

Perhaps the plates are grounded internally?

[GambleFury]

Okay its not running. You lost me now what are the plates and all i have to do is get a new battery then?

[wrightz28]

the lead plates in the battery. How old is it? Is it exposed to alot of road shock? Is secured down by the hold down bolt?

[GambleFury]

Its is about 1 year or so but the car has been sitting for about 6 months and it is held down with a bolt.

[wrightz28]

Hmm, what is the voltage across the battery?

[GambleFury]

18.5

[wrightz28]

Ok square one, what caused you replace the alt. in the first place, this problem? Or not charging at all?

[GambleFury]

Ummm it wouldn't start so i toke it to my shop at school and the culprit was a gasket leak in the throttle body fix that then found out that my fuel pump went out fix that. then we i brought it home the voltmeter in the dash was jumping up and down from 9 volts to 14 so i checked it with a voltmeter on the alternator and it said 22.8 and this is where i am not an i replaced the alternator 3 times 2 times in the last month.

[wrightz28]

Alright, what loses me is even if the car sat for 6 months, the max a alt. would put out is 15.5v to try and charge it (kids don't try this at home unless you like nuking alternators). On rare occasions I've heard of them getting as high 18v, but that's rare. Only thing that would make alternator go full field like that is if the feed wire to the battery was not connected, or a ground. But you said you have the voltage at the battery, and drop accross the ground cables is good. If the battery is under warrenty I'd take it back.

Something is telling the voltage regulator in the alternator that the battery is flat out dead. And at this level it's an open in the circuit csomewhere.

BUT, you wouldn't happen to have any enemies at this school or pranksters would ya?

[GambleFury]

lol no but i will take it back and see about a new one THANKS for your help!