Whirlpool Refrigerator Evaporator Fan Motor Humming, Not... | appliancefaults.com

Technical Background:

The evaporator fan motor circulates cold air throughout the refrigerator. It's typically a DC motor controlled by the main control board (MCU), which receives signals from thermistors and other sensors. The MCU regulates the voltage supplied to the fan motor. Some newer models have variable speed ECM fan motors. Voltage paths include low voltage DC from the main board via wire harness to the fan motor itself.

Symptoms:

The homeowner reports a humming noise coming from the freezer compartment of their Whirlpool refrigerator. The freezer is cold but the evaporator fan motor is not spinning. Food in the fresh food section may not be cooling properly.

Possible Causes:

Evaporator fan motor is physically blocked by ice buildup.
Fan motor windings are failing, causing the hum but insufficient torque.
The motor's electronic control board (if equipped) has failed.
Wiring harness or connector issue between the main control board and the fan motor.
Low voltage being supplied to the fan motor from the main control board.
Thermistor failure causing the control board not to activate fan.

Solution:

1

Unplug the refrigerator from the 120V AC outlet or turn off the dedicated breaker in the breaker panel.
2

Access the evaporator fan motor. This usually requires removing shelving, the evaporator cover, and ice buildup in the freezer section. Use a hair dryer or steamer to melt ice buildup if necessary.
3

Manually spin the fan blade. If it doesn't spin freely, the motor is likely seized and needs replacing.
4

Check the voltage to the fan motor using a multimeter. Locate the connector at the motor. Set your multimeter to DC voltage, typically 12V DC. If no voltage is present, trace the wires back to the main control board.
5

Inspect the wiring harness and connectors for damage or corrosion. Repair or replace as needed.
6

If voltage is present but the motor isn't running, the motor is likely faulty and should be replaced. Obtain the correct replacement motor part number.
7

Reassemble the refrigerator and plug it back in or turn the breaker back on. Monitor the fan motor's operation.

Safety Warning:

Disconnect power to the refrigerator before performing any repairs. This appliance operates on 120V AC, which can cause serious injury or death. Lock Out/Tag Out (LOTO) procedures should be followed. Wear appropriate safety glasses.

Prevention:

Regularly defrost the refrigerator, especially if it's an older model without automatic defrost. Ensure the door seals are clean and intact to prevent excessive moisture buildup, which can lead to ice formation. Check the defrost drain line periodically to ensure it's not clogged.

Expert Tip:

Many Whirlpool refrigerators have a diagnostic mode. To enter, press and hold the door light switch, then press the refrigerator temperature 'WARMER' button three times within 6 seconds. Error codes can then be displayed, which can help pinpoint the fault. Consult the service manual for your specific model for detailed instructions.

Frequently Asked Questions

•What is the correct part number for the evaporator fan motor for my Whirlpool refrigerator model?

You can find the correct part number by locating the model number of your refrigerator, usually inside the refrigerator compartment. Then, search for parts using the model number on appliance parts websites or consult a parts distributor. They can help you identify the correct motor.

•How do I test the thermistors in my refrigerator to determine if they are faulty?

Thermistors can be tested using a multimeter set to measure resistance (Ohms). Disconnect the thermistor from the circuit. Compare the resistance value at room temperature (around 70°F) to the thermistor's specification chart (usually found in the service manual). Significant deviations indicate a faulty thermistor.

•Where is the main control board located in my Whirlpool refrigerator?

The main control board is typically located behind an access panel, either at the top rear or bottom rear of the refrigerator. You'll need to remove the panel to access the board. Refer to your refrigerator's service manual for the exact location for your specific model.

Whirlpool Refrigerator Evaporator Fan Motor Humming, Not Spinning: Troubleshooting Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What is the correct part number for the evaporator fan motor for my Whirlpool refrigerator model?

•How do I test the thermistors in my refrigerator to determine if they are faulty?

•Where is the main control board located in my Whirlpool refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: