i know this is a very old thread but i have to ask. the truck is a 03 aviator. i replaced the battery because was bad. every since then i have the battery light on. i had the alternator checked and it was good. i swapped for a known good one just because. i am still not getting a charge. battery voltage is reading 11.75 and the alternator is reading the same. I have checked the wires for continuity and all is good. i have rest both the grounds that i have found. is there more?
if don't figure this out there is going to be a giant bonfire in my yard with a lincoln as a starter.
How's the condition of your cables? As mentioned these cable to have poor connection to the terminals and along the line. If you can try to clean the contacts or use another lines to see if it will make any difference.