Bad Alternator or Bad Battery?

[KKneipper]

I went to leave work the other night, and my car was idling just fine while I was letting it warm up. As I pulled out of the parking lot, the RPM's weren't climbing like it should, but my boost gauge (which I know is accurate) was reading a full 11 psi. The car felt like it does when you punch the gas in an auto. It was spooling but felt like it couldn't catch.

The next morning I went out, started the car, let it warm up, and drove to work. It was boosting like normal and everything seemed fine. I have come to the conclusion that it is only acting sluggish when I have to have my headlights on. However, the windows, radio, heater, and dash lights are all working properly.

I disconnected my + cable from my battery while the car was running, and after about 30 seconds it dies out.

So, is it my alternator, or my battery? I took the car to Autozone to have them test both, and they said that they could only test them if I took them off the car. When I went outside to take the alternator and battery out, they told me I couldn't do it in their parking lot... So I said screw Autozone.

 

[liquidz28]

im with ya on that, +1 bad alt.
car should continue runnint w/o battery.
least it isnt hard to replace.

 

[Indian]

Do you have a voltmeter? That would give you a better answer to whats going wrong. Just see what the voltage is when the cars running,and the static voltage when the cars off. Autozone may not have a portable battery tester,only a standing tester,and thats why they said bring it in.

 

[southrneclipser]

you shouldn't take your positive battery terminal off like that. I know it works to tell you if your alternator works but it can also spike your ecu causing it to fry out and screwing your whole car up. A voltemeter would help but you can still pop out th ealternator and take it somewhere to test it. They do it for free so you might as well do it before you buy a new one.

 

[liquidz28]

you shouldn't take your positive battery terminal off like that. I know it works to tell you if your alternator works but it can also spike your ecu causing it to fry out and screwing your whole car up. A voltemeter would help but you can still pop out th ealternator and take it somewhere to test it. They do it for free so you might as well do it before you buy a new one.

+1 on the take the alt out for testing, allways test suspected parts if they are testable.

i dont agreen on the removing the battery terminal though, just my observation the ecu has protection agains overvolting in most cases, im not sure how yours is setup if you think about it, if that was the case you wouldnt be able to get a jump w/o toasting your car

heres a volt meter method, tho it will be pretty hard to do with your alt so low in the car.
http://www.ehow.com/how_2283281_test-car-alternator-power.html

 

[KKneipper]

Thanks for the help guys. The only thing that got me puzzled was that I was talking to a mechanic from a chrysler dealership, and he was there back when they were still selling Eagle's. He said that the Mitsubishi wiring is set up differently (due to interference), and that he never did a test by pulling the positive cable off, but that it may be different, and the ECU may sense that the battery isn't connected, and make the car stall out. I don't have to be to work until tomorrow evening, so early tomorrow I'm going to pull the alternator and use the wife's turbo to run the alternator and battery down.

I wish I had a volt meter, I've had a few issues lately that would make it handy to have one.

 

[liquidz28]

Thanks for the help guys. The only thing that got me puzzled was that I was talking to a mechanic from a chrysler dealership, and he was there back when they were still selling Eagle's. He said that the Mitsubishi wiring is set up differently (due to interference), and that he never did a test by pulling the positive cable off, but that it may be different, and the ECU may sense that the battery isn't connected, and make the car stall out. I don't have to be to work until tomorrow evening, so early tomorrow I'm going to pull the alternator and use the wife's turbo to run the alternator and battery down.

I wish I had a volt meter, I've had a few issues lately that would make it handy to have one.

i pulled mine off 10 mins ago...still runnin

 

[KKneipper]

Ok, good to know... It's probably the alternator then.

 

[rlacasse1]

Take the car to an Oreillys. They have a little machine that can test the battery and alternator in the car. At least the when in my hometown does.

 

[KKneipper]

I finally got a hold of someone at Autozone that knew what she was doing. She pulled the machine out and tested it while the car was off and while it was running. The battery is holding 12.2 volts (with the car off) and the alternator is holding 60.2 amps. Looks like its gonna be time for a new alternator.

Checker/O'Reilly won't test anything if it requires popping the hood. They claim its because of insurance reasons. So I go to Autozone to get my tests, and go to Checker to buy my parts.

 

[jdub1992]

i also have a 1996 talon tsi AWD, just replaced battery.. At idle, the alternator reads 12.6 volts, but It will only charge the battery if I am at high RPMs. The alternator is 2 months old, what could be the problem? it just wont charge.

 

[tsi1991awd]

DSM alternators are known to be crap...I've replaced the one in my old 1g and just got this 1990 and had to replace the alternator. AT LEAST yours wasn't so bad that the battery drained and you couldn't keep the car running unless it was jumped. My shit just died on me going to work and then I knew it was the alternator. It takes literally less than 10 minutes to pull the alternator man...just pull it out, take it to Autozone...they put it in a little machine and if it says FAIL then it's bad. Easy.

I set my battery on the slow charge for 24 hours....replaced the alternator (YES buy it from Autozone...it will have a LIFETIME warranty) I have gone through 3 alternators now, only having to buy ONE because the other two were completely FREE due to warranty. I'm pretty sure your alternator is dead. Pull it out, stick it back in. It takes me less time to re-install it than it does to remove it.

 

[liquidz28]

too bad you cant retrofit an alt from a 97+ z28 (that has all power options)
mines at 179,000 original miles and that bad boy is still goin strong ...if i could only get my lt1 stroker under the hood of my awd dsm....;p
all the parts from shucks/oriely are lifetime warrenty also, the folks at autozone are more helpfull...i'd buy from where customer service hasnt been hindered by corperate america...just my 2 cents...customer service better than genuine parts imo.

 

[KKneipper]

I've replaced alternators on previous vehicles I've owned, and I'm not complaining about it, and I know how easy it is. New alternator at Autozone is going to run me 138 bucks with the core charge. I'm lucky that it's not completely fried out, so I'm hoping it lasts until I can find one for cheap on craigslist or at the junkyard.

i also have a 1996 talon tsi AWD, just replaced battery.. At idle, the alternator reads 12.6 volts, but It will only charge the battery if I am at high RPMs. The alternator is 2 months old, what could be the problem? it just wont charge.

What you're describing is a glazed/loose belt. If the alternator is that new, then the belt is probably just slipping past the pulley on the alternator, and not actually spinning it. The reason that it's charging at high rpm's is because the belt is spinning faster, and it's probably just barely catching it enough to charge.

all the parts from shucks/oriely are lifetime warrenty also, the folks at autozone are more helpfull...i'd buy from where customer service hasnt been hindered by corperate america...just my 2 cents...customer service better than genuine parts imo.

I prefer going to Checker/Shucks/O'reilly because of the fact that the service is always better there. The parts are better quality, and The people there actually know what they're talking about. They just can't test anything while it's on your vehicle.

"Talon's didn't come with turbos and you're going to #### your engine up if you rigged one on."-Guy at Autozone

"I know we have an NGK sticker on the door, but we don't carry NGK, They're junk."-Another guy at Autozone

"Sorry, Insurance reasons prohibit us from checking your CEL."-Guy at Checker

At least Checker sounded like he knew what he was talking about.

 

[asb2106]

Well look at it this way...

If you know what your talking about.. it doesnt matter how much of an idiot the person helping you is, as long as they have the part you want.

I could give a shit where I buy parts, whoever has it and its not junk, Im cool with it. Autozone has felpro, I get those there, I get alot of things from autozone infact, oil, filters, little accessories, Ive gotten calipers there, there gold series ceramic pads dont suck.. dont get their rotors tho ( I have had 2 sets warp)

I prefer my good parts come from Napa, and everything else is based on price. WHo cares how much the store knows really, if you dont know what your doing you probably shouldnt be doing it.

Thats why Autozone does so well and makes the corporate dollars. Idiots go in and buy a ton of little parts trying to guess at hte problem with the vague code readings that autozone has, and it really ends up costing you more in the long run.

Do your own leg work with the details, cause trying to rely on any of those places is asking for troubles.

 

[knochgoon24]

too bad you cant retrofit an alt from a 97+ z28 (that has all power options)...

You can install one from a Saturn for a little more juice.
http://www.dsmtuners.com/forums/articles-electrical-wiring/272646-saturn-alternator-swap.html
http://www.dsmtuners.com/forums/cus...tant-improvements-saturn-alternator-swap.html

Or you can buy a rewound one from a decent shop that will output a few more amps. They often have warranties too.

 

[nothingfiction]

You can always look into the Canadian OEM alternators, as they are rated at a higher amp for our cold weather.

 

[jdub1992]

ok, I bought mine from NAPA and I have warranty so I am getting it replaced just incase. As for the belt, it may be that. The belt kept squealing so I just tightened it but it still squeals on occasion. that may be plausible, thanks man and it is a new belt so I will let you know once I get it put together. I also fixed a loose positive battery terminal connection to ensure it charges properly.

 

[liquidz28]

ok, I bought mine from NAPA and I have warranty so I am getting it replaced just incase. As for the belt, it may be that. The belt kept squealing so I just tightened it but it still squeals on occasion. that may be plausible, thanks man and it is a new belt so I will let you know once I get it put together. I also fixed a loose positive battery terminal connection to ensure it charges properly.

that loose positive could have been your problem from the get....
should have been your first objective is to check terminals for damage, tightness...
i had charging issues about 4 months ago, i knew i needed a new battery so i got one anyways, mine tested to have a bad cell or two, and the terminals where tight, but the terminals on the inside where cone shaped and the battery post is cylindrical so contact was minimal, changed to the steel type from a 04 durango, now its 100% contact, and cleaner looking...if your terminals are crappy, grab some steel loop style.

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[knochgoon24]

A wire brush and some electrical grease go a long way in cleaning and protecting battery terminals.

 

[jdub1992]

hey I did do the positive terminal check first, that didn't solve the issue. I also checked the belts and they seemed ok. Well I got the new alternator and they checked the old on at NAPA where I got it from originally. The guys at autozone are dumbasses. they said it was pushing 12.6 volts, the guy at NAPA did it right, it was pushing less than 1. problem solved and I drove her to class and to work today thanks guys.


jared

 

[knochgoon24]

Good. Mark the thread as resolved.

 

[liquidz28]

hey I did do the positive terminal check first, that didn't solve the issue. I also checked the belts and they seemed ok. Well I got the new alternator and they checked the old on at NAPA where I got it from originally. The guys at autozone are dumbasses. they said it was pushing 12.6 volts, the guy at NAPA did it right, it was pushing less than 1. problem solved and I drove her to class and to work today thanks guys.


jared

right on
congrats!