Blowing the dash lights instrument fuse - 94

My '94 has all of a sudden been blowing the fuse that runs my dash instrument lights. Everything else is normal and it runs good.....just hard to see the gauges as night. Anyone out there have a clue on where to begin looking for a "short?" When I put a new fuse in, it will operate for about 2 minutes before blowing the fuse. Thanks for any come-backs on this one.