What is the amperage rating on the switch?
Unfortunately the manufacturer does not supply the amp rating for this switch.
The switch for the Downdraft #14-39-59 / 3 (414429 )wires need to be replaced - not available
What is your advise to replace it with?
With the wiring for the unit being discontinued, in order to repair the wiring you would need to replace the wiring with the same gauge wiring that is on the unit.