I have a 94 Chevy Blazer full size. When starting the truck in the morning the battery gauge is in the red and the battery light is on. The truck starts fine and after 30min the gauge returns to normal (about 12) or a little higher and the battery light goes away. I have had both the battery and the alternator tested and they are fine. I have a bad feeling I am going to burn out my alternator. At some point when the battery is in the red and I have my radio on, it starts to flicker on and off. I have run out of ideas.

 

i would guys that the alt is going bad, possible the battery too. Start with the alt. If the problem continues replace the battery