Just got my wife a 2002 Explorer XLT last week. Nice vehicle except that we didn't have the code to the keyless entry pad and could not lock the doors from the drivers side (inside) lock button without first turning the ignition switch to the run position. Also the key pad would not lock the doors when the 7/8 9/0 buttons were pushed, unless the ignition switch was again in the run position. Doesn't do much good to lock the vehicle with the key in the ignition in the run position, or any position for that matter when you can't use the keyless entry. It didn't come with any remotes.
Anyways, long story short, I was able to find all the info I needed (on here) to get everything working like it should be. Located the factory code, found the small ground wire in the drivers door broken, fixed it as per this thread, programmed in wife's code, checked all functions. Everything working as it should. Best of all, it only cost $00.00!!!
Thanks for all the great info guys! Now to get a second key and a couple remotes.