2002 speedometer, dome light and windshield wipers all stopped working

I have a 2002 Ford Ranger that just yesterday--after a long dry spell--had the windshield wipers turned on only to find they've stopped working. I don't believe it's a coincidence that the speedometer and the dome light have also stopped working.
We've checked all the fuses--they are all good.
Checked the relay fuses under the hood--they appear to be all okay.
Put new tires on it today and asked the guy there...he checked everything we'd already checked out plus a few other things and said he couldn't find the problem.
He also mentioned that it could be a circuit board behind the dash that got burned out. Anyone have any idea what would cause three seperate things to stop at the same time that run on different fuses and all those fuses are good? At first we thought it might be the windshield wiper motor...speedometer and dome light don't have anything to do with that motor,though, does it? At a loss as to where to go now...speedometer and dome light aren't that big a problem but I think the windshield wiper problem needs fixin' before letting son take it back to college. Any ideas? Thanks.

Debbie

I am having the same problem, did you find out what was wrong?