Defrost timers are key to the refrigerator working properly. The timer keeps the heat coils from freezing up. This enables the heat coils to remove the warm air. The refrigerator then pushes the cool air throughout the refrigerator.
Locate the defrost timer. It could either be underneath the refrigerator or behind the refrigerator.
Remove the panel that is below the refrigerator doors. This will either snap off by pulling it outward from the refrigerator. It could also be attached by screws. If it is attached by screws then unscrew them and pull the panel off. If the defrost timer is located on the bottom of the refrigerator it well be attached to the corner panels.
Remove the rear bottom panel with a Phillips screwdriver or a socket wrench. Pull the panel off. If the defrost timer is located in the back it will be located on one of the corner panels.
On the front of the defrost timer there will be a circular notch. Take a flat head screwdriver and turn it counter clockwise.
Turn the notch until the refrigerator fan has shut off. You will hear it. This has reset the defrost timer.
Place the back or front panel back on by either snapping it on or replacing any nuts or screws back into place. The defrost timer will kick back on within 20 minutes.