I just got a used Kenmore washer dryer combo model #417.94702300. Wired it as 120 volt.
The washer works fine but dryer does not work at all. Does the dryer section of this
Combo machine require 220 volts to function? I can't figure it out. How many thermal
Switches are in this unit? Can I test them with an ohm meter? If yes, what should the
Resistance be? Thanks, Frustrated.

The dryer takes 240 volts. The resistance on any safety should be zero. You may need to tear it down and clean it, too.