Why is my refrigerator clicking on and off?

When a residential refrigerator clicks on and off repetitively or emits a rhythmic clicking sound every few minutes without successfully starting the cooling cycle, it is almost always caused by a failing compressor start relay, a bad thermal overload protector, or a locked compressor motor. The clicking sound occurs when the electrical start relay attempts to energize the motor, but because the motor is thermally overloaded, locked mechanically, or receiving insufficient power, it fails to turn over, tripping the safety overload switch. You can troubleshoot electrical parts by unplugging the fridge and inspecting the relay module. You can verify that your corrective action is successful when replacing a burnt-out start relay or clearing thermal overloads allows the compressor to engage and run smoothly.