More than likely it is not the switch but a resistor located on the
passenger side of the firewall just under the hood.  Pretty inexpensive part
from the dealer, but the harness is probably wiped out as well.  I picked up
the new resistor from the dealer, and then went to the boneyard for a
plug/harness in better condition.  Cut the wire harness and soldered the
used one on, then installed the new resistor.  Be sure to get the wires
right our your speeds may end up in the wrong position on the switch - not
fatal, but interesting....

Hope this helps!