Maytag Refrigerator Air Damper Stuck Open: Troubleshootin... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) regulates the temperature inside the fresh food compartment by controlling the air damper. The MCU receives temperature readings from the thermistor. Based on these readings, the MCU sends a signal to the damper motor to open or close the damper, regulating the flow of cold air from the freezer into the fresh food compartment. Voltage supplied to the damper motor is typically 12V DC.

Symptoms:

The refrigerator section is excessively cold, leading to frozen food. The freezer section may be working normally, but the fresh food section is much colder than usual. You may hear a constant fan noise, indicating the damper is not closing to regulate airflow.

Possible Causes:

Faulty air damper motor
Defective thermistor (temperature sensor)
Damaged or blocked air damper assembly
Malfunctioning electronic control board (ECB)
Wiring harness issue between ECB and damper motor

Solution:

1

Unplug the refrigerator from the 120V AC outlet.
2

Locate the air damper assembly inside the refrigerator, typically in the fresh food compartment near the top.
3

Visually inspect the air damper for any obstructions or damage.
4

Using a multimeter, check the damper motor windings for continuity. An open circuit indicates a bad motor.
5

Check the thermistor resistance using a multimeter. Compare the reading to the temperature/resistance chart in the service manual. An incorrect reading indicates a faulty thermistor.
6

Access the electronic control board (ECB) and check for any visible signs of damage. With the fridge plugged in, use a multimeter to check the voltage to the damper motor when the door is closed (simulating cooling demand), you should see approximately 12V DC.
7

If the motor and thermistor are good and the ECB is supplying voltage, suspect a wiring harness issue between the ECB and the damper motor.

Safety Warning:

Always disconnect power to the appliance before performing any repairs. Use proper Lock Out/Tag Out (LOTO) procedures to prevent accidental energizing of the circuit. Be aware of high voltage components on the electronic control board.

Prevention:

Regularly clean the refrigerator to prevent food debris from blocking the air damper assembly. Check the door seals to ensure a tight seal and prevent warm air from entering, which can cause the system to work harder.

Expert Tip:

Many Maytag refrigerators have a diagnostic mode that can be accessed by pressing a specific sequence of buttons. Consult the service manual for the correct sequence for your model. This mode can often provide error codes related to the damper motor or thermistor.

Frequently Asked Questions

•What is the typical resistance value of the thermistor at room temperature (72 degrees Fahrenheit)?

The typical resistance value of the thermistor at 72 degrees Fahrenheit should be approximately 5k to 10k ohms, but consult the service manual for the specific value for your model.

•Where is the electronic control board (ECB) located in this refrigerator?

The ECB is typically located behind the refrigerator, near the bottom, or behind a panel inside the refrigerator compartment.

•How do I test the air damper motor without removing it from the assembly?

You can test the damper motor by accessing the wiring harness and applying 12V DC directly to the motor terminals. Observe if the damper opens and closes. Be careful not to short any wires.

Maytag Refrigerator Air Damper Stuck Open: Troubleshooting and Fix

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the typical resistance value of the thermistor at room temperature (72 degrees Fahrenheit)?

•Where is the electronic control board (ECB) located in this refrigerator?

•How do I test the air damper motor without removing it from the assembly?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: