Why does battery indicator gauge on 1998 Chevy Cheyenne occasionally suddenly drop sharply while driving with a new alternator and battery all connections check fine could the new alternator be bad?
When cold, the alternator produces more electrical energy to recharge the battery. After things warm up a little, the electrical energy drops back to maintenance mode, producing enough energy to operate all of your electrical component and maintain the charge level of the battery. At that point you'll see a drop on the gauge. Also, any device which turns on suddenly will cause the voltage level to drop briefly. It's normal and unless you are unable to start the vehicle in the morning or see the gauge in the red area, or the yellow area for an extended period, you're probably ok.