HELP is my alt. dead?

DaSuprawolf

Im SICK of N/A
Dec 29, 2005
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ChicagoLand
ok, for a couple days i've been hearing a wine from the engine bay and then today i go to start my car and its dead, so i jump it and i get home fine, only like 2 miles. later that night i go to start it and it barly starts and then it slowly dies and stals, i go to start it again, and nothing, and volts read around 5, so i jump it again and it will only run if i keep the rpm's around 2500 or else the volts will drop and car will stal. also the higher i rev, the brighter my lights get. i figure its the Alt. because if it was the battery, once it started it would be fine right?

i got the Alt. out and going to test it at autozone tommarrow, this stinks, Alt.'s are expincive.

Does this sound like a bad Alt. ??
Please let me know. Thanks -Brian
 

Nick M

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Sep 9, 2005
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Sure sounds like a bad charging system. You ran the battery down when the system wasn't charging. I woldn't be putting an alternator from Autozone on your car. Toyota rebuilds are pricey, but they are done in house and last as long as new units.
 

supraman7mgte

Shut up,bitch!!
Apr 1, 2005
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simple test.
fully charge the battery.
run the car at idle and then pull off the positive terminal of the battery.
if it continues to run,the alt. should be okay(but i'd take it somewhere just to have it checked)
but if it dies,then your not putting out sufficient voltage to keep the car running.
 

Nick M

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supraman7mgte said:
simple test.
fully charge the battery.
run the car at idle and then pull off the positive terminal of the battery.
if it continues to run,the alt. should be okay(but i'd take it somewhere just to have it checked)
but if it dies,then your not putting out sufficient voltage to keep the car running.
-1.

Don't ever do that. It creates a voltage spike that could destroy vehicle electronics. I know cavemen at Autozone and other places have done it, and gotten away with it, but it is dangerous.

I didn't really minus one you by the way.
 

amd_hcds

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Dec 20, 2005
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get a volt meter and fully charge your battery and start the car and check the voltage on the battery in my opinion if it's anything below 13 then you need to replace\rebuild your alt. if not turn on your headlights\fog lights and turn on your AC if you have it working and check the voltage if again below 13 then it's just not sufficent in other words if you run your headlights&fog lights & AC you'll get to same point you are at now very soon
 

bigal0043

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Jun 29, 2005
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i have never heard of a car blowing electronics by pulling the the battery while its on... i have always heard just to pull the battery to see if the car will stay running...

when your car is off and you put a battery on that must put out a spike as well...


but check our terminals as well they could be coroded
 
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GotBoost?

I do
Nov 25, 2005
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I can't remember where I read it, but I did read in some manual that disconnecting the bat. cable will spike the system. So do that at your own risk.
As far as "when your car is off and you put a battery on that must put out a spike as well..." that's not true. When the car is off, the alternator is not sending any power anywhere. And the power needs of the engine and electrical system are different when the motor is off vs. on.
 

b005t3d

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Jul 14, 2005
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wow, okay. lets get some shit srtaight. never disconnect your battery while the car is running. it will die wether the alt is good or not, we dont have oldschool muscle cars. its a computerized car. it will mess things up. and when you do take your batt out, always disconnect the negative first and put it on last. you need to take it to a shop where they have a vat 40 so they can properley load test the alt while the car is running. another thing, your alt is not designed to recharge your battery. it is designed to merely keep the function of the car running while the car is one.the battery is a storage unti. test your battery with a volt meter. if it is below 12.6 significantley, charge it and test it again or get a new one. get your alt load tested the proper way.also, check all your connections for being loose or corroded.
just remember, your alt is not designed to recharge your bat. if you try to use it for that, go buy another alt cuz that one is done. or will be shortly. if your alt puts out less than 14.5-15, get a new one or get yours rebuilt.
 

supraman7mgte

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Apr 1, 2005
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okay,maybe i was wrong about the pulling of the positive terminal while running. BUT if you did, (and i'm not saying to) how would the car die? the alternator is providing juice to the elc. system,thus keeping it running,and yes,the battery is just a storage device to start the car.
i suggest again to get the alt checked,load tested and all that crap.
throw your battery on a charger and let it juice up for about 8 hrs or until sufficiently charged. (most chargers have a 10 or 2 amp setting,i use 2 for deeper charges)
and make sure you don't have anything that is draining your batt while the key is off (dome lights are famous for this)
 

Nick M

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supraman7mgte said:
okay,maybe i was wrong about the pulling of the positive terminal while running. BUT if you did, (and i'm not saying to) how would the car die?the alternator is providing juice to the elc. system,thus keeping it running,and yes,the battery is just a storage device to start the car.
Current can not flow with out a ground path of some sort. It is not just a storage device. It is spike suppression and a stabalizer.
 

b005t3d

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Jul 14, 2005
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some one that agrees? the car will still die if you take the battery off because, the cars computer still relies on the battery for its 5 volt reference signal. with out it, no runny run.
 

Supracentral

Active Member
Mar 30, 2005
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NO battery = NO buffer between your electrical components and the altenator. The car battery often serves as a big capacitor to protect against voltage peaks.

b005t3d said:
some one that agrees? the car will still die if you take the battery off because, the cars computer still relies on the battery for its 5 volt reference signal. with out it, no runny run.

Negative - it will run (I've seen it). But it's very bad for the entire electrical system.

Just have the altenator (and the battery) load tested - most shitball auto parts stores do it for free these days.

As a general rule of thumb, when one goes, the other usually isn't far behind. They are part of the same system, and a weakness in one causes a strain on the other.
 

b005t3d

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Jul 14, 2005
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i forgot to post that when one goes. the other is on its way. thanks there supracentral. mine went that way too. had to replace the alt and then the battery 2 days later.