Whirlpool TruCool: Troubleshooting Temperature... | appliancefaults.com

Technical Background:

The Whirlpool TruCool refrigerator uses a Main Control Unit (MCU) to regulate the temperature. The MCU receives input from temperature sensors (thermistors) located in the fresh food and freezer sections. It then controls the compressor, evaporator fan, condenser fan, and damper to maintain the set temperatures. Voltage paths include 120V AC to the compressor and fan motors, and low-voltage DC to the sensors and damper motor.

Symptoms:

The homeowner reports that the temperature in the fresh food section of their Whirlpool TruCool refrigerator is fluctuating. Food is sometimes freezing, and other times it feels too warm. There may also be excessive condensation.

Possible Causes:

Faulty Damper Control
Defective Temperature Sensor (Thermistor)
Airflow Obstruction
Evaporator Fan Motor Failure
Inefficient Compressor

Solution:

1

Unplug the refrigerator or turn off the breaker at the breaker panel.
2

Locate and inspect the damper control assembly. Check for any visible damage or obstructions. Use a multimeter to test the damper motor for continuity.
3

Access and test the temperature sensor (thermistor) with a multimeter. The resistance should correspond to the temperature inside the fresh food section. Refer to the service manual for the correct resistance values at different temperatures.
4

Inspect the airflow vents for obstructions such as food packages or ice buildup. Clear any blockages.
5

Check the evaporator fan motor for proper operation. Ensure the fan blades are not obstructed and that the motor is running smoothly. If the motor is not running, test it with a multimeter for continuity.
6

If the compressor is suspected, check its operation using a multimeter to check windings. Check the start relay and overload protector with your meter. A licensed technician may be needed to check refrigerant pressures.
7

After completing the repairs, plug the refrigerator back in or turn on the breaker. Monitor the temperature in the fresh food section to ensure it is stable.

Safety Warning:

Disconnect power before servicing. Lock Out/Tag Out (LOTO) procedures must be followed. Capacitors can hold a charge even after the unit is unplugged. High voltage is present when the unit is powered on.

Prevention:

Clean the condenser coils every six months using a vacuum cleaner with a brush attachment. Ensure proper airflow around the refrigerator. Avoid overpacking the fresh food section, which can restrict airflow. Check door seals regularly and replace if damaged.

Expert Tip:

Access the service mode by pressing and holding the Freezer Temp Down and Refrigerator Temp Up buttons simultaneously for 5 seconds. This will display error codes and allow for component testing. You can use a 1/4-inch nut driver to remove the rear panel for access.

Frequently Asked Questions

•What are the typical resistance values for the fresh food thermistor at 35°F?

Refer to the Whirlpool TruCool service manual for the exact resistance values. However, as a general guide, you can expect the resistance to be in the range of 5-10k ohms at 35°F. Consult the wiring diagram or component location chart to confirm pin locations.

•How do I properly test the damper control motor?

First, visually inspect the damper for any obstructions or damage. Then, use a multimeter to check for continuity across the damper motor terminals. An open circuit indicates a faulty motor. Refer to the wiring diagram for correct pinout.

•Where is the best place to purchase replacement parts for my Whirlpool TruCool?

Authorized Whirlpool parts distributors are the best source for genuine replacement parts. You can locate them on the Whirlpool website or by searching online. Be sure to have your model number handy.

Whirlpool TruCool: Troubleshooting Temperature Fluctuations in Fresh Food Section

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What are the typical resistance values for the fresh food thermistor at 35°F?

•How do I properly test the damper control motor?

•Where is the best place to purchase replacement parts for my Whirlpool TruCool?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: