95Juan

I've got a bit of a problem. a while back, my battery went dead, so i replaced it (maybe 2-3 weeks ago). all the time my alternator had been slowly going bad. at the final point, my voltage (on the stock voltmeter) would peg itself at the very top (18?), then if i would put the car under load (gas it, build some boost, etc), the meter would go down to like, 14, maybe 13.

so i took the alternator out.

it spins completely freely. as if it's got bearings in there and NO resistance.


i got a rebuilt one, which had a pretty good amount of resistance (would spin maybe 3 or 4 rotations, when put on it's "face")

i installed it, and my voltage still pegs at 18+ at times, although it will go down to 14 or 13 after a while of driving.

i've only been driving it for 1 day (with the new alternator in) but i'd like to get rid of any stupid little electrical gremlins that could jeapordize my enjoyment with my car this weekend.

will this just even itself out as the alternator "wears in" to the car/electrical system/battery?

or do i have other problems?


TIA.

KuHL 951

If it's charging at 18v the voltage regulator on that new alternator must be bad or your gauge is hinckled. Since it happened before the new alt. I would vote for the gauge being bad. It's easy to test it with a voltmeter. Check the voltage at 2000 rpm at the battery if it's 18 you have a bad alternator with a fried diode pack, if it reads 13-13.8v and the gauge says 18 it's your gauge. Next thing is turn on all your high current accessories (high-beams, defroster, stero, AC, expresso machine) and see if the alternator voltage drops less than 12v.at the same rpm. Voltage should drop some from an unloaded state. If it is charging at 18v you should not drive the car, it will ruin little things like the DME, battery, and most of your electronics.

ibkevin

*drool, espresso machine* console mounted of course!

95Juan

that's the thing, is that when it pegs, i see no movement no matter how many accessories i put on.

now, when i had the subs (2-12's), and it would peg, i would turn them up, and it would drop to 16 or lower on a hard note.

now when it pegs at 18, doesnt it seem like the little red light at the bottom should come on? like, when you get too low voltage, the light comes on, shouldnt it come on when it's too high?

and the other thing is that it's a "new" alternator. and the meter is showing the same symptoms as the old one.


this tells me it's either


A- something else in the electrical system
or
B- the meter itself.

i have the rest of the day off, so i'm going to go buy a voltmeter and check it at the battery when it pegs, just to see if it's the meter itself, or if it's something else.



if the meter is still pegging (inside the car and on a separate voltmeter) and the alternator has been replaced, what else could it be?

or can it not be anything else and i'm just having ****ty luck?











PS- the thing is, that i can leave the car COMPLETELY alone for a few hours, and when i come back- kapow- pegged the meter. when i turn the ignition to ON it pegs the meter, then when i start, it's still pegging.

on OCCASION it will peg on ON, peg after i start, then after 2 seconds, drop to 12-13.


i want to think it's just something to do with the meter......i REALLY hope it's something to do with the meter cuz i honest to God dont want to replace the alternator for a 3rd time.

Note- there is a *brand new* voltage regulator in it. the one that came in the alternator i got was kind of worn, so i bought a totally new one.

streckfu's

Do you have access to a multi-meter to measure the actual output? Or try taking it to a Pep Boys or Autozone to have them test it (it's free).

KuHL 951

Juan...you just answered your own question. There is no way a 12v battery can produce 18 volts with the motor off. It's the gauge amigo unless you have 2 batteries hooked up in series.

mavfan

haha i just watched the simpsons last night and Homer was driving around with like a popcorn machine, deep fryer, fax machine, all this stuff hooked up to his cigarette lighter. it was pretty funny. he drove off into the ocean and sent a fax of SOS just in time to send help. lol

95Juan

ok, that's what set me off. cuz i was like "ok.....that makes NO sense at ALL" because sometimes it pegs the meter, then sometimes it goes to like, above the 12 mark, etc.


i'll check with a voltmeter later today to double check.....


because right now i turned on the AC/fan, full lights (high beams too), brake lights, and then when i pressed the window switch, i got some belt squeal.




i dont know. i'll have to go get a multi-meter just to be safe. i dont want to kill my DME this weekend or anything......


thanks for the help.

Dilberto

Mira,

Your voltage regulator brushes are going south. Change them soon! Your car will drain the battery hella quick, and strand you when you least expect it.

Zach

KuHL 951

Zach - Sorry to disagree with you but why would a new alternator with new voltage regulator/brushes be going south if he just put it on 3 nights ago? If you read his posts he has 18 volts with the key in 'on' position/engine off. That's not caused by failing brushes. How does an alternator make 18 volts with the engine off? A failed diode pack can produce higher than normal voltage but only if the engine is running. Another thing, as brushes wear down to their limit voltage/amperage drops it doesn't increase. It has to be a bad gauge if his description is correct.

95Juan

yeah, plus i know what bad brushes are. bad brushes are what WAS in there. like i said, i can put the old alterantor on there and it will spin freely when placed face down on the pulley.

the new one will not.

and the new one has a brand new voltage regulator.

brand new as in......brand new.


ok, steve, i'm almost thoroughly convinced it's the meter just acting up, because when i have the car on, it'll peg at 18, and flucutate occasionally (it's going down, and staying normal alot better now). but when it pegs at 18, if i turn on the AC/fans, lights, etc, etc, it will immediately drop down to 12, and then when i turn everything off, it goes back to the 13 range.


again, i'm heading to radioshack to get a multimeter just to be 100% sure before tomorrow.



thanks for everything................again.

bearone

the voltmeter in the dash isn't that accurate.

when just started after sitting overnite you shold see upper 13's to low 14's on the multimeter.
as it warms up you should see mid 13's or higher.

87951

RM512

See 'overvoltage' on this page:
www.systemsc.com/problems.htm

95Juan

ok, i just bought a multimeter at autozone ( ) and it shows around 13 when the meter in the car is pegging.

this is in AC, right?

KuHL 951

Told Ya it's in DC not AC