Have attached 3 prints These are for the 03 expedition But they are the same for the 04 expedition
In print 81-01 you will see fuse #1 (10A) AND CONNECTOR C270b PIN 6 this should be where the jumper from the cutoff switch was installed.
In print 24-09 you will see at the bottom of the contacts for the fuel pump relay connector C270k pin 3 the dark green/yellow wire That wire goes to the cutoff switch and was the wire that was cut
Now look at the top of the contact and you will see reference to page 24-03 Y
on page 24-03 you will see Y and it goes to fuse 34 (20A) it also goes to C270a
If you re-attach the wire at the cutoff switch and install a jumper from C270a pin 10 red wire to connector C270k the fuel pump should run and will be protected by fuse #34.
This will get the expy running until you can replace the fuse box or replace the relay.
I would be very careful about buying a used fuse box as that year and the 03 had the same problems A fuse box with a newer build date would be ok but not with a 02,03, or 04 build dates