How can I determine if it is the defrost thermostat or the defrost heater?
Answer Hello Frank. You can test the defrost heater WR51X465 and the thermostat WR50X129. They should read closed for continuity when cold. You can test this with a multi-meter TJMA-DMT3. Here is a link on how to use a multi-meter. Hope this helps. http://forum.appliancepartspros.com/oven-repair-including-ranges-cooktops/4810-how-check-continuity-ohmmeter.html