Mazda Repair: mazada batter light, alternator belt, jumper cables

Question
my 2002 mazada tribute battery light came on and i went to autozone to have it tested. they said the battery and alt was good and there was no problems. later that evening when i was getting gas the card would not start. i got a jump but before i can make it to the street it died again. can u help me with this problem? i dont know if its the alt or a fuse

Answer
The alternator has an internal regulator, a switch that cycles the output of the alternator as the battery requires more or less power.  The dash light indicates either there is no output from the alternator or there is too much.  The alternator can be producing power but if the regulator is bad then it will not get the signal to do it's job.  Two parts in one.  You can jump start the car.  When it runs disconnect the jumper cables if it dies then the alternator/regulator have failed.  Even with a dead battery the alternator should provide enough power to keep the car running.  The battery may be salvaged by putting it on a low amp charge overnight.  Now on a simpler note, check the alternator belt be sure it is in place and has ample tightness, of course with the engine not running.