How To Test the Compressor Relay

The compressor relay's purpose is to start the compressor. A faulty relay can result in the compressor failing to cycle on. The relay is accessed from the lower rear of the refrigerator. In the photo below the compressor is labeled "A", the relay is located in the terminal box which is located at the position labeled "B".Caution: Please read our safety information before attempting any testing or repairs. Before testing a compressor relay, unplug the refrigerator to avoid an electrical shock hazard. Also, if the compressor uses a capacitor, it must be discharged first to avoid the risk of electrical shock.
The compressor relay can be accessed by removing the terminal cover box. The cover is held on by tension or with a retaining clip.

Beneath the terminal cover is found the compressor relay (labeled "A" below), overload protector (labeled "B") and the electrical terminals of the compressor motor.Remove the compressor relay by pulling it straight off from the compressor. Pull the wire off of the side terminal of the relay. It is connected with a slip on connector. Firmly pull the connector, do not pull on the wire. You may need to use a pair of needle-nose pliers.Inspect the connector and terminal for corrosion. If either is corroded they should be cleaned or replaced.There are two types of relays you may encounter, wire coil and solid state. If the relay has an exposed wound wire coil it can be tested for continuity. Otherwise, the relay is of solid state design and requires specialized equipment for testing. Test the compressor relay for continuity using a multitester. Set the multitester to the ohms setting X1.With the relay upside down, place the probes into the terminals labeled "S" and "M". The multitester should display a reading of zero ohms, indicating continuity (or if using a continuity tester, it should light up).With the probes still in place, turn the relay over. You should hear the click of the magnetic switch engaging. The multitester should now display an ohm reading of infinity (or the tester should not light up).Turn the relay upside down again, place the probe on the "S" terminal and place it on the side terminal labeled "L". The multitester should now display a reading of zero ohms (continuity). Turn the relay over and the reading should change to infinity.With the relay upside down place one probe on the "L" terminal and the other probe on terminal labeled "M". The multitester should display a reading of zero ohms. Turn the relay over and the reading will stay the same, zero ohms.If the compressor relay does not pass all of these tests, it should be replaced.