Check for a blown alternator fuse.
Are we sure that the alternator is not charging? The battery could be old and worn out to the point that it won't take or hold a charge. HTH. -Jim
Looking for a Used Grand Prix in your area?
CarGurus has 2,628 nationwide Grand Prix listings starting at $1,450.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts
Related Models For Sale
Used Cars For Sale