Ford Repair Questions? Ask a Mechanic for Answers ASAP
Ok with an early build you have 2 relays involved. Both are on the back side of the interior fuse panel. How the system works is the GEM module grounds the coil side of the battery saver relay which provides power to the interior lamp relay which is also grounded by the GEM module which then provides power to the interior lamps.
Now if I understood you correctly you can manually turn on the interior lights at the lights and another question is does the glove box light work?
Ok if glove box light works then this eliminated the battery saver relay so you need to start at the interior lamp relay. Look on page 212 of your owners manual and it should list the relays there. The interior lamp relay is no.7, try swapping it with the relay next to it(rear washer pump) and see if this corrects your problem.