How to Replace an ADC Module in a Frigidaire

Safety Precautions

• Before performing any repairs on your refrigerator, it is vital that you shut off the power supply. Replacing the ADC does not require you to move the refrigerator away from the wall, so it is often easier to turn off the breaker in your home's service panel. Disconnecting the power supply eliminates the possibility of injury.

Defrost System

• The defrost system consists of a defrost heater, a defrost thermostat and a defrost control. The defrost control energizes the defrost heater, which melts any ice or frost as it forms on the evaporator coils. The defrost thermostat is installed on the evaporator coils, and it prevents the defrost heater from turning on if ice is not present. The thermostat has a circuit that closes when ice and frost are present, allowing the current to pass to the defrost heater. If no ice or frost is detected by the defrost thermostat, the circuit remains open and the heater does not turn on.

Defrost Timer

• Older Frigidaire refrigerators utilize a defrost timer, while many models manufactured after 2002 rely on an ADC module. The defrost timer is a rotatory timer that, depending on the model of your refrigerator, energizes the defrost heater every eight to 12 hours. The ADC module does not contain a timer. Instead, it detects the position of the defrost thermostat, energizing the defrost heater as needed.

Replacing the ADC

• The ADC module is located in the control panel at the top of the refrigerator's fresh food compartment control panel. To access, remove the screws securing the control panel, as well as the damper housing that runs along the left side of the top of the freezer wall. Disconnect the control panel wire connector from the roof of the fresh food compartment, then disconnect the light switch wire connector from the control panel. Pull the damper thermistor out of the left wall, then remove the control panel. The ADC module is located in front of the air damper, in the air damper housing. Remove the screws securing the ADC module or depress the tabs, depending on model. Install the new ADC module by securing it to the housing and transferring the wire connectors.