Many people have had pro with the defroster wire kinking, and that's a hard
one to fix... I've been messing with mine repeatedly... I guess the right
way would involve dash removal, but I got mine pretty darn straight
reaching in through the lever slots.
  I had some aluminum rod, but an old screwdriver or would work too.
Mine, the control wire just bent/kinked rather than pushing through the
housing to move the actual defroster wire, and once that happens, it's a
pain to get the kink out so the wire moves rather than just bends again at
that kink.
   So I filed a notch to catch that wire with a peice of rigid aluminum...
I got the rod lined up with the kink and straightened it right out by
prying....Now the wire is straight and goes into the housing
properly...Gotta take out the ashtray and stereo to see