2006 GMC Sierra "Battery Not Charging Light"?

[Christopher]

I have replaced both battery and alternator and the "battery not charging light" still comes on! I have had both items re-tested and they are working properly. Any Ideas?

 

[Brady]

the computer code could just need reset try leaving the negative terminal unscrewed from the battery over night and then put it back on in the morning this may reset it. if not take it to a garage