Thank you in advance for the help.

I have a 2000 Chevy Silverado (5.3L V8). About two weeks ago, started noticing some issues and pulled the alternator and had it tested; it failed quicky. The truck had started showing the volt gauge going down as I was driving, the weird thing was that when I would come to a complete stop and take off, everything would go back to normal. The volt gauge would go back to normal and everything would be fine for a little while. Rather than chancing it, I went ahead and replace the alternator.

Everything worked fine for about a week and then the issue came back. So I went ahead and replaced the battery too. The battery is good and we've taken out the new alternator and tested it and it is good too. The same thing is happening when the voltage will go down to around 10 or 11 volts (sometimes lower) and now SOMETIMES, when I stop and take off, the voltage will go back up to 14 volts or a little bit above. It's doing this very rarely now and seems to just be running off of the battery.

Anyone have any ideas?

 

Did you check it with a meter at the battery? It is possible that the volt meter on the dash is wrong

 

The volt meter is correct. The battery has been tested and is running dead when the truck is on. It seems as if the alternator is not charging it; but its happened with two (2) new alternators and two (2) batteries.

The strange thing, like said before, is that when the volt meter in the dash shows that the battery is slowly dying when the truck is in use, if you come to a complete stop or rev up the motor (sometimes), something starts working and the lights get back up to normal brightness and the volt meter goes back to where it should be.. It's like things start working again for a few minutes and then stop again after that.

 

Check the battery cables for corrosion and bad spots at the battery as well as the other end of the cable. Sounds like there may a bad ground connection. Also check the wires from the alternator to the battery.

 

Yep,sounds like a bad ground somewhere.

90% of odd intermittent electrical gremlins can be traced to a bad ground.