2004 Chevy Silverado battery not charging?

[amehtyst_p]

I have a 2004 Chevy Silverado 1500 and I recently replaced the battery and alternator because I started to get the computer message of 'battery not charging' and the battery light will come on as well. The problem is that I'm still getting these messages even after replacing both the battery and alternator. Does anyone have any ideas what is causing this?