>I imagine that most of you have experienced this wild flashing of the 
>temp. gauge for no apparent reason...the van is NOT overheating, nothing 
>is wrong, it just goes nuts.

It's telling you the coolant is low!!!  The switch is in the main reservoir, 
check the coolant.  If the light comes on while driving then stop, this is 
the first warning of problems you'll get.  If the light then goes off when 
engine is at idle you have an airbubble in the system and need to have it 
bled.  Looking at the reservoir/coolant level when parked and @ idle rev the 
engine up and see if the level drops, if so you have a bubble.   Tim Smith