i think the alternator on my blazer may be on the way out but im not really sure... the volt meter on the dash is moving up and down and the lights are dimming in accordance with the movement in the gauge... i cant find my voltmeter anywhere to do a external check but i think thats the problem... if it is its the third or fourth one we have had to put on this thing in the last six years.. stupid chevys :( i know that when the car is off there should be 12v current on the battery but when its running it should be putting out around 14v correct?