I had one of these on an old '67 bus I had in high school.  It worked OK
in dry climates, but it did have this annoying tendency to drip right on
the foot of the bed.  Anyway, an RV store should be able to provide you
with a manufacturer's name and address.  The pla-cool required an rv-type
demand water pump, and a water tank.  This pump pressurizes the water
lines to have household-like water on demand.  If you find or install a
demand water pump and a water tank, then hook the water line to the cooler
it should work well.

John Brown