My 96 chevy Tahoe wont

Check the big red wire on the back of the alternator for power. The wire likes to get corroded in half inside the casing but is still held together BY the casing. you can even take a jumper cable from the positive side of the battery to the big/single wire on the back of the alternator. Now , you could have a bad ground also. take a voltmeter or test light and with the ground of the tester on the ground of the battery check for power on the case of the alternator. Another thing , does the alternator or charge light on the dash light up woth the key off? the alternator knows to "start-up" or "field-up" by the power it recieves through the bulb before the engine is started. once the engine starts the small brown wire on the alternator goes hot and shuts the light on the dash off cause it now has power on both legs of it. if the bulb blows then the alternator won't field-up. good luck. Scott

check your charging voltage and make sure the alternator has power to it