My battery light cam on yesterday in 1998 Blazer 4.3 L Vortec. The voltage on my dash was way down (about 11 or 12 volts) when it has always read just above 14 volts. So today I pulled my battery and took it to get tested at Napa. They told me I needed a new on. After putting it in I still am experiencing the same problem with the light and the reading on my dash. Do I have a problem with my alternator? Any ideas what might be causing this issue? It seems to be running fine. Turns over on first try. Any ideas would be great. Thanks.

 

I would not have replaced the battery. Sure it was probably low from driving it around with the battery powering everything, but even a full battery won't supply 14V... Your alternator is most likely at fault here. Have the full charging system tested.