WHERE OH WHERE is the fuel pump relay on a 2001 Ford Excursion V10 ?

You probably have two fuse boxes, one under the hood and one under the dash. Some Fords have the fuel pump relay built into the fuse box and it cannot be replaced so you have to replace the whole fuse box. Your owners manual will have a diagram of the fuse boxes and relay locations. If you don't have one, Ford should have a copy you can download.

My 2003 Expedition recently crapped out and it was the built in fuel pump relay in the interior fuse box. $400 and 4 hours of labor and it runs again!

Some Fords have the fuse box located below the windshield and small leaks eventually corrode things. It started out as a fuse connection that was going bad and then the relay went. We almost always garage it but after 14 years and 160k miles it was the only serious problem we have had with it.

I have found that if you "exercise" the 4wd it will work without problems. I make a habit of switching my vehicles into 4wd at least once a week.