88 vanagon weekender was coming home from a fruitful = weekend when all of the sudden the water temp idoit light started = flashing.  We pulled over and checked the water level and the temp gauge - all were = working fine.  Started the Van up again and took off, cruised along just = fine for about 50 milkes and then started flashing again.  Pulled over and = checked my water level connection (good), and whatched my temp level-- all = normal.  Drove a little slower ( 60 F outside @ 63mph- slowed down to = 55mph)  Didn't come on the whole way home (100mi).  Never comes on around = town.  Any thoughts??