Advancing a Top Mount Refrigerator’s defrost timer is done from the inside of the refrigerator section. The timer will be located behind the control that adj the refrigerator’s temperature.
Follow the center console area back, located in the middle you will see a small cut out, this cut out is the base of the defrost timer, using a small screw driver advance the timer until the refrigerator’s compressor kicks on or until the heater has voltage applied.
With an ohm meter you can manual check the refrigerator defrost thermostat and heater. The timer sends power to the compressor during cool mode and then sends power to the defrost heater for “Defrost” using a volt meter and advancing the timer to defrost 110v should be present at the refrigerator’s defrost heater.
The timer will rotate one direction, when the timer make a sharp click you know it has advanced to the next cycle.