[VAL] Fan runs backwards

["jcchome" <jcchome@xxxxxxxx>]

I just noticed that the fan over the stove blows instead of sucks.  I
had cleaned it up last spring, but just now used it.  I assumed that I
had wired it with the wrong polarity.  I changed the wiring and it still
blows.  I then took the fan out and tested it on the bench.  Either way
12 vdc is connected, the fan runs the same direction, and that is the
wrong direction.  I thought DC motors ran both directions depending on
the polarity of the input voltage.
 
Now what?  Anyone have a suggestion?
 
Best Regards,
   Jim