Battery/Alternator issues

[gtarbmx]

So I accidentaly left my lights on last night and the auto shut off feature didn't work for some reason.

I drove to a restaurant with some friends (4 miles). On the way back my battery indicator started going off and a couple minutes later all the warning lights started going nuts, the headlights dimmed and radio turned off, then the RPMs started dropping so I pulled over and the 4runner died. I started it a couple of minutes later and drove a mile home, then it died in front of my house.

Could this be a case of a bad alternator or a bad battery, or something else?
Thanks for your help ahead of time.

 

[gtarbmx]

to add:
i have a subwoofer system with a capacitor, it shows a full 12v.

 

[Rommel]

Do you have a battery charger? Also try another spare battery?

 

[gtarbmx]

i'm about to go get one.
should i just take the battery and have it tested?
also, how do you check the alternator?

 

[Rommel]

It doesn't seem like the alternator is blown since all you did was forgot to turn off the headlights. If you were running the car, and you pulled one of the battery connector, then the alternator would be fried. I suggest taking the old battery and see if its good, get a new one and connect it in to see if it runs. Narrow down the checklist.

 

[gtarbmx]

will do.
i'm just confused by two things.
why would the battery not charge while driving, and why would the engine die when there's no power, shouldn't it just run off the alternator if the battery is bad?

 

[gtarbmx]

so i charged the battery and it's fine.
but when i start the 4runner the battery light shows up.
looks like a bad alternator at this point.
what do u guys think?

 

[ebg18t]

before you start replacing anything get it tested. Most the chain part stores will test the alternator/battery for free. This will give us more info to work with. I also wonder if any of your battery -> alternator wires are disconnected/corroded/falling apart.

 

[chaz]

:iagree: also is that the original Panasonic battery?

 

[gtarbmx]

got the battery tested, it's fine.
i'm taking it to s shop tomorrow to do the lift anyway (too many seized bolts to do it without shop tools).
i'll let you guys know what the issue was.

 

[riceandpho]

have you check the alt-s fuse ? its in the engine compartment. check some fuses first.

 

[gtarbmx]

it was the alternator, should've known.
you should always check all the connections before replacing the alternator though. i'm glad i got a good mechanic.

i gave her a front lift too.

 

[riceandpho]

so is it the big fuse or the little fuse?

 

[gtarbmx]

the fuses were fine. just the alternator decided to quit.

 

[T4R04LTD]

I was gonna say the alternator is bad. I had the same thing happened to me and it was the alternator that was bad.