I have 2003 f150. Alternator is good but not charging battery, battery lite
is on.

 

I've had a similar problem. My 97 F150, on cold mornings has to get a jump due to a sluggish turn, then it stops trying all together. The battery and alternator tested as good, so im putting new terminal connectors on today to see if that helps. Either way Ill post what happens, hopefully its not something too big. Good luck!