hah i see this a lot on those year model fords, it's just a crappy wiring job. I'm guessing somebody that worked in the ford plant didn't know what he was doing and messed up a couple, lol.
Holy crap. I have been searching the internet for the last 2 hours trying to find this. This also happens on my 99. I have not tried tapping the dash, but I would like a more permanent solution. I do realize this post is almost 3 years old, but has anyone figured anything out?