not heating

Hello, could not find a tech sheet for this model. There are only three parts to the defrost system, heater, bi-metal and the timer. If you have continuity through the heater you will need to check the bi-metal next for continuity while it is in the freezer and cold. if you have continuity through the bi-metal you will have a bad timer. if no continuity through bi-metal you will have a bad bi-metal.

Have you checked the Freezer defrost bi-metal thermostat # 297216600 to see if its open ? This is in series with the defrost heater that you say has continuity correct ? If your timer contacts are good and sending voltage down to the defrost thermostat then you have an open therm. you can test the defrost therm by bypassing it to see if the heater comes on. You only have three parts to this defrost system 1) Defrost timer #215267800 2) Defrost heater 3) Defrost therm. # 297216600