ok heres the deal, my alternator went out so I replaced it.

gauge read 13/14 as it should, then one day it went all the day down like it was just running off the battery. I did the usually, revved the engine up to get it to spin, nothing. So I took it back cause its lifetime warranty and it was pumping 14 volts so I took it back home n installed it and the gauge read the same. I tapped the dash close to the volt gauge then it went up.

Every now n then it goes down to like 8 and i tap the dash and it goes back up.

How can I fix this? My baby has to have no glitches, even one as minor as this.

 

You could get lucky and find a loose connection to the gauge or source..chances are you'll have to replace it though.

I've the same issue with my car...started about when I had 16K or 17K miles on it.