Battery light on
get battery and altenator tested at nearest auto part store such as autozone. a bad battery will make battery light come on.also sometimes a bad battery will make altenator work alot harder causing altenator to go bad as well.
I just had the same problem with my truck, and what it was -- is a bad regulator in the alternator.
Looking for a Used F-150 in your area?
CarGurus has 12,413 nationwide F-150 listings starting at $352.
Search Ford F-150 Questions
Ford F-150 Experts
Related Models For Sale
Used Cars for Sale