This 4-wire connection defrost timer acts like a clock, continually advances and alternates between activating the cooling cycle and the defrost heater. You can turn the dial on the defrost timer clockwise to advance it into and out of defrost mode. If the refrigerator is too warm, the freezer section is too warm, or the freezer is not defrosting, you might need to replace the defrost timer. This defrost timer is 120-volt, 60 Hz and genuine OEM part. Pleaser remember to disconnect the power to the refrigerator before starting the repair.