I've got a 2002 Toyota Camry with the four cylinder motor in it. The car sat for several months, so I went ahead and changed the battery because it was dead. I also did some other basic maintenance like spark plugs, and air filters.

After starting the car it will run for about 5 minutes or so and then it dies. I used a voltmeter to verify that the alternator was charging the battery the entire time and it does up until about 5 minutes. Then, the vehicle will die. The voltage will drop from about 14.2 volts to 12.4 volts. If I continue to let it run, then the car will eventually cut off.

I have changed the alternator twice, thinking that the original alternator was bad and that maybe I got a faulty one from the auto parts store, still no change. I even temporarily ran a 4 gauge wire directly from the positive post on the alternator to the battery. Nothing changed. The belt is nice and tight and the fuses are good from what I can tell.

I'm kind of at a loss here and hoping to get some help and suggestions on what to do next. Any help is appreciated. Thanks.