Check for a blown alternator fuse or fuseable link wire going to alternator.
hate to say it, but an alternator can be bad right out of the box. I would have it tested. actually have had this happen.
True...happen to me also...more than once...
Looking for a Used Wrangler in your area?
CarGurus has 16,540 nationwide Wrangler listings starting at $2,590.
Search Jeep Wrangler Questions
Jeep Wrangler Experts
Related Models For Sale
Used Cars For Sale