OK here's the problems:

My battery light came on in my car a few nights ago. When I got to where I was going, I killed the engine and tried to restart ( wondering about the battery light ). It wouldn't crank at all, all interior lights dimmed out, etc. I came back 30 minutes later to charge the battery with a friend. I decided to give it a try before charging and the car started up fine, but ran a little rough ( nothing extremely out of the ordinary. The car is 11 years old and has a good 175k on it. ). I drove around a day or 2, with hardly any problems then suddenly the same as above happened again, but didn't crank after the 30 minutes.

I then charged it for about 15 minutes, barely got it cranked and took it for a spin around the block. It cut off half way around the block, dead in the water.

Today, I swapped in 2 different batteries: 1 out of my truck and 1 out of my dad's camaro, both working fine just before I swapped 'em in. Nothing worked, the battery wouldn't put out any power to the car.

I tried charging the batteries, just in case, and the lights wouldn't even come on at all while connected to the other vehicle. I then disconnected the battery and clamped the jumper cables directly to the battery cable and it cranked immediately. As soon as the positive jumper cable was disconnected, it died. I assumed because of the alternator being bad, but the more I think about it, the alternator might get its grounding from the battery cable.


I'm thinking its a bum alternator, but I was looking for others opinions before I yanked the alt off and took it to the parts house.

My thinking is the time it cranked connected jumper cable to battery cable was because it was using the other vehicles alternator, but I'm not sure how that works. Any info would be highly appreciated.

I hope I explained this well enough >.<


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knowah
1996 Pontiac Sunfire 2.4L GT

Alternator sounds like the best opiton.

The first time the battery light came on, it told you that something went wrong with the charging system or something went out. When you cranked it after it wouldnt start the first time is cause you gave the battery time to rebuild. But you can only do that to a battery X amount of times (depending on what battery you got). Then when you charged it a bit then it died around the block...thats when your battery gave up. The battery cant provide power to the car alone for long (more like 15mins to an hour if your lucky)

-This points to an alternator because your charged battery wasnt getting amps from your alternator to maintain the car

HOWEVER....
Because you got two different batteries from other cars and they didnt work either... that says more than a alternator. If you hooked up the jumps to it and it dies when you removed it from the positive, then it might mean that the cables are corroded on the inside or burnt (the way to test for corrosion is to feel how stiff it is. If it feels like you might break it when you bend it together or it starts to snap, crackle and pop, then its corroded really bad). The reason why I say this is cause your giving the battery more juice than its supposed to from your current battery and from another by forcing more power thru the cable, to the battery, to the car.

Okay, to make this short...
an alternator or/+ bad cables/connection or/+ bad battery
Or it can be as simple as a blown fuse or relay.
Please dont tell me you jumped it backwards (not to be a smart a** or nothing)

Hope it helps...
Hope I explained it better back to you.







...They just HATE it when you ...POINT - LAUGH - then DRIVE OFF AND AWAY-!...

I think you have a problem with Battery Terminal connections-see para 6, and read para 7 before you get a new alternator..

1.The charging system failed in some way and the Battery/Charge light informed you that it had.

2.As said, the 30 minute wait allowed the battery to recover sufficiently for the car to start, ran a little rough probably because the voltage was low

3. Charged it for 15 minutes-this is not long enough to properly charge the battery-so it barely started and then the voltage dropped so low the engine stopped.

4. [Today, I swapped in 2 different batteries: 1 out of my truck and 1 out of my dad's camaro, both working fine just before I swapped 'em in. Nothing worked, the battery wouldn't put out any power to the car.]

5. [I then disconnected the battery and clamped the jumper cables directly to the battery cable and it cranked immediately. As soon as the positive jumper cable was disconnected, it died. I assumed because of the alternator being bad, but the more I think about it, the alternator might get its grounding from the battery cable.]
Note:- The alternator is grounded by being bolted to the chassis.

{This is not a good thing to do. The voltage spikes etc from disconnecting the battery whilst the engine is running can take out diodes and damage computer type things in the system, however!.}




6. I think your battery terminal connections on the Positive and Negative battery cables need a good cleaning until the contacting surfaces are "shiny clean", reconnect and try again with a known charged battery.

I base this on the fact that two known good batteries were fitted but neither made anything work, but connecting the jump leads directly to the cables and everything worked.




I would have added "Clean the Negative cable where it connects to earth/chassis (Wouldn't be a bad idea- but this must be OK because you then say [ I then disconnected the battery and clamped the jumper cables directly to the battery cable and it cranked immediately.] so the earth connection must be OK , also the Fusible links must be OK

[As soon as the positive jumper cable was disconnected, it died.] This reinforces the Battery terminal needing cleaning, as soon as the jump cable is removed there is no power to the rotor of the alternator to energise the rotor and produce electricity. Secondly, there is a high resistance between the battery terminals and the battery cables so battery voltage stops at the battery terminals and does not reach the electrical system-engine stops..

7. [I'm thinking its a bum alternator, but I was looking for others opinions before I yanked the alt off and took it to the parts house.]

I would at least get hold of a voltmeter/digital multimeter and check the voltages in the system

a. Voltage across the battery terminals-engine stopped--12.5volts on a good battery
b.Voltage at the large (BATT) terminal on the alternator and earth-engine stopped (This terminal ALWAYS has Battery +12 volts on it-or should have)--This should be the same voltage as a.
c.Voltage across the battery terminals-engine running--This should be up to 14.8 on a GM vehicle.
d. Voltage at the large (BATT) terminal on the alternator and earth-engine running (Take care doing this)This should be up to 14.8 on a GM vehicle.

Test b. is another way to check if the battery terminals are making good contact(At least the Positive one) and if the Fusible link is good. This cable goes from the alternator, through a fusible link to the positive battery cable to the battery.

Hope this helps, post back if you have any more questions


Alont

ok, first off thanks for the replies guys.

After my original post, I did a bit more experimenting. I put the batteries back in their original cars and decided to replace the battery from the sunfire for sh*ts and giggles. I dropped the battery in and the car cranked fine, I did so a couple times, but the battery light is still on on the cluster. I can't find my owner's manual but I believe that means the battery isn't getting recharged by the alternator, right? I know it was like that on older oldsmobile cars/gm trucks.

The weird thing about the new battery is both batteries that I tried work fine in their original car/truck. They're also the same size as well.

By the way, I forgot to mention in my original post ( sorry ) that I checked the wires for being stiff/corroded and cleaned the battery terminals/ground connections before I started.

Everything seems to point to the alternator, but it looks like such a p.i.t.a. to remove due to the crowded engine bay, which is why I'm asking advice before i try it . I tried reaching the bottom bolt on the alternator and it almost seems impossible without removing the coolant reservoir and/or the side panel of the car. If you guys/gals believe its the alternator, I could use some tips of reaching it with least amount of effort . I've seen the walk through's here and on autozone's site, but by the pictures they have a ton more room than I have to work with.


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knowah
1996 Pontiac Sunfire 2.4L GT

The voltage check with engine stopped and then running is the simplest way to confirm it is the alternator.

If you get 14 ish volts at the alternator but not the battery terminals it could be a fusible link in the main charging cable.

Some shops will check this for you for free but a meter can be purchased quite cheaply


Alont