Whirlpool Refrigerator: Clicking Sound, Compressor Start... | appliancefaults.com

Technical Background:

The Main Control Unit (MCU) sends a signal to the compressor start relay, which provides a temporary boost of voltage to start the compressor motor. The overload protector prevents the compressor from overheating. The relay circuit typically involves 120V AC.

Symptoms:

The homeowner reports a repetitive clicking sound coming from the back of the refrigerator, near the compressor. The refrigerator is not cooling properly.

Possible Causes:

Failed compressor start relay/overload.
Compressor windings shorted or open.
Low voltage to the refrigerator.
Faulty Main Control Unit (MCU) not properly signaling the compressor.
Locked rotor (compressor mechanical failure).

Solution:

1

Unplug the refrigerator and disconnect power at the breaker panel. Verify zero voltage at the outlet.
2

Locate the compressor start relay/overload assembly on the compressor.
3

Using a 1/4-inch nut driver, remove the cover to access the relay.
4

Visually inspect the relay for burns, cracks, or a burnt smell. If present, replace the relay.
5

Use a multimeter to test the relay for continuity. An open circuit indicates a failed relay.
6

Check the compressor windings for shorts using a multimeter set to ohms. Low resistance between any two terminals suggests a shorted winding, indicating compressor failure.
7

If the relay and compressor windings appear good, check the voltage at the outlet with a multimeter. It should read approximately 120V AC. Low voltage can prevent the compressor from starting.

Safety Warning:

Always disconnect power to the refrigerator at the breaker panel before performing any repairs. Use proper Lock Out/Tag Out (LOTO) procedures to prevent accidental energization. High voltage is present in the compressor circuit and can cause serious injury or death.

Prevention:

Clean the condenser coils regularly (every 6 months) with a vacuum and brush attachment to ensure proper airflow. Avoid overloading the refrigerator, which can strain the compressor.

Expert Tip:

If the compressor is running but the refrigerator is not cooling, suspect a sealed system issue (refrigerant leak or compressor inefficiency). A common quick test involves checking the compressor dome temperature after running for 15 minutes - it should be hot to the touch. If it's barely warm, the compressor may be failing.

Frequently Asked Questions

•What if the start relay tests good, but the clicking continues?

If the start relay tests good, it is likely a compressor issue (locked rotor or internal short) or a problem with the MCU. Further diagnostics will be needed to pinpoint the exact cause.

•How do I test the compressor windings?

Disconnect all wires from the compressor. Use a multimeter set to ohms. Measure the resistance between each pair of terminals. There should be continuity between each terminal, and the resistance should be roughly similar (a few ohms). A reading of zero ohms or very low ohms indicates a short. Infinite resistance indicates an open winding. Also, check each terminal to the compressor body - there should be no continuity (infinite resistance), otherwise the winding is shorted to ground.

•Where can I find a replacement start relay?

Replacement start relays can be found at appliance parts retailers, both online and in brick-and-mortar stores. Be sure to have the model number of your refrigerator to ensure you get the correct part.

Whirlpool Refrigerator: Clicking Sound, Compressor Start Relay Failure - Symptoms & Troubleshooting

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•What if the start relay tests good, but the clicking continues?

•How do I test the compressor windings?

•Where can I find a replacement start relay?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: