I recently replaced the temp sensor in the radiator that
controlls the radiator fan with a cooler version so it would
come on sooner...at 85 degrees Celcius.  Well...the other
day, my fan came on full blast as i was looking for a place
to park at night in the rain...and it would not shut off
even when I shut the van off ..pulled fuse, etc.

It turns out that the temp sensor leaks..and coolant went
right into the plug and shorted it out...causing the fan to
be on high at all times...
just an FYI tidbit.
steve