Alternator or Battery problem?

[Trojan97]

I have a '95 Chevy Beretta that has been sitting undriven for about 1.5 years, I recently went to start it up to begin using as my "quick trip" warm weather car and I was unable to start it- no locks, no lights, nothing. So I boosted it with my other car and it was able to start fine, I left it running for about 15-20 minutes and then it suddenly died again. I boosted it again and then turned the key and it started fine, I left it for a few minutes and then turned the car off only to find there was again no power whatsoever.

So I took it out for a drive today, drove around the neighbourhood for about 20 minutes hoping the alternator would charge it. When I returned home I turned the car off and then immediately tried turning it on again. Car was instantly dead once again.

Can anyone guide me on a possible solution? I replaced the alternator and battery 2 summers ago so I was hoping I wouldn't have to replace them but I can't think of any other problem it may be.

Any help is appreciated.

[GoinAllTheWay]

1.5 yrs without being used is gonna take a toll on a battery. Not really sure that 20 mins of driving is going to be enough time to charge a good battery anyways. I'd buy a charger (pretty sure they are cheap) and let it do its thing over night. Try again if if the battery gets killed right away, I'd say that's a pretty good sign the battery is done.

If you don't want to buy a charger, driving the car for at least an hour should let you know if the battery is holding a charge or not, especially if you happen to have a battery tester.

[Slava]

I think that the battery should charge enough in 20 minutes though? I would say that because you replaced the alternator 2 years ago it should still be good and its likely the battery. I'm not a mechanic and basically just going by anecdotal fixes though.

[Rathji]

A dead battery can kill a alternator. So it may be both.

I am willing to bet the battery is pooched at this point.

Start the car, undo the battery cable. If it stops running then there is something wrong with the alternator as well. It might just need a new belt, tightening etc, or might need replacing.

[Slava]

Originally Posted by Rathji

A dead battery can kill a alternator. So it may be both.

I am willing to bet the battery is pooched at this point.

Start the car, undo the battery cable. If it stops running then there is something wrong with the alternator as well. It might just need a new belt, tightening etc, or might need replacing.

Really? How come?

I thought that anytime you disconnected the battery the car would stop running also...doesn't it complete the circuit?

(Maybe I should stick to the other threads!)

[4X4]

Battery.

Take it out, take it to Auto Value, have it tested, buy a new one, put it in, turn the key and listen to the bitch purr.

[wooohooo]

You could always take the battery to Canadian Tire. They have a machine that will test the life of a battery to see if you need one... for free. If not, then they just charge it and give it back to you.

Probably the easiest way, then go from there and know if you need a new battery or not

[ken0042]

Originally Posted by Rathji

Start the car, undo the battery cable. If it stops running then there is something wrong with the alternator as well. It might just need a new belt, tightening etc, or might need replacing.

The car stopping running would be an indication that it was made sometime after ~1988.

When the ignition lock snapped on my 89 Beretta, the mechanic told me to drive it there and remove the negative post to stop the engine.

I would say it is likely the battery after that long- I would also let it run for an hour to see if it will charge up. If you or a friend has a voltage tester, when running the car should be putting out about 14-15 volts.

[GoinAllTheWay]

Originally Posted by Slava

I think that the battery should charge enough in 20 minutes though?

I doubt it to be honest. More modern cars, maybe not, but older cars for sure. I used to have a 280ZX that I parked during the winter months. I would have to charge the battery over night as I learned the hard way that a battery that hadn't been used in a while had a hard time keeping a charge.

On top of that, if the car spent the last 1.5 yrs outdoors, it's probably toast.

[DESS]

It's the battery 100% for sure.

[FlamesAddiction]

If you're in doubt, take it by a shop. Some mechanics can test your alternator for you in a couple of minutes and won't charge for it.

[Trojan97]

That's exactly what I needed to hear, thanks very much for the excellent input everyone. Most appreciated!

[Rathji]

Originally Posted by Slava

Really? How come?

I thought that anytime you disconnected the battery the car would stop running also...doesn't it complete the circuit?

(Maybe I should stick to the other threads!)

Apparently, it can put undue strain on the alternator which can cause it to stop working. I guess having a weak alternator can cause a bad battery for kinda the same reason. So I may have it backwards.

As for the circuit, the way a cars electrical works it pulls current from the battery when the alternator is not producing current. If the alternator is producing (enough) current, it doesn't need the battery.

Originally Posted by ken0042

The car stopping running would be an indication that it was made sometime after ~1988.

That is something I didn't know. I drove a work truck without a battery in it this summer so that's what I was basing that statement on. Couldn't tell you how old it was though, we were transporting it to be put on some company land for junk storage.

[Winsor_Pilates]

95% sure it's battery

[Ford Prefect]

Yup, sounds like a battery. After a year and half the electrolyte or whatever the battery fluid is called may well be dead and that could be why it wouldn't charge.

[ken0042]

Originally Posted by Rathji

That is something I didn't know. I drove a work truck without a battery in it this summer so that's what I was basing that statement on. Couldn't tell you how old it was though, we were transporting it to be put on some company land for junk storage.

Yeah, I know my old 84 Trans Am would run without a battery. I'm not sure if it has something to do with fuel injection or a newer computer. There was a couple of times we did that so we could put the good battery into another car to get it somewhere.

[alltherage]

I hate battery/alternator problems. You risk ruining both by troubleshooting. I would take out a voltage meter and check the battery first.

[tussery]

Take a volt meter (if you have one) to the battery and the battery should be around 12v +/- .5V after you have measured the battery voltage put a load on the battery by putting the vehicle in accessory and measure again. Again it should be about 12V +/- .5V if it is not then there is a good chance you need a new battery. If it checks out start your vehicle and again meter the battery, this time with the vehicle running you should be reading around 14V. If not it is most likely your alternator.