Has it been raining(hard)? You can pull the passenger side kick panel & check fuses & see if water has leaked onto the fuse panel from above. Windshield are known to leak on earlier models.
To check fuse panel: Open passenger door fully, remove threshold cover by pulling up (no fasteners), pull kick panel out and back toward door opening (remember position of door seal related to panel), 'Pop' fuse panel from top and use DVM to check fuses. You may be able to visually check with bright flashlight. Check also if water has dripped on panel.
If you don't have one, you can download a Expy service manual here:
https://www.scribd.com/doc/249677473/2003-Expedition-Navigator-Service-Manual
Thanks to Hamfisted