Troubleshooting a Refrigerator Start Relay
A refrigerator start relay is a device that jump-starts the compressor inside the refrigerator. If the refrigerator start relay is burned out, then the compressor may not work and the interior of the fridge will not freeze. Since the compressor is a very important part in the refrigeration system, it needs to have a working refrigerator start relay in order to work. If the refrigerator is warming up and making some strange clicking noise, this may be an indication of a damaged refrigerator start relay.
Removing the Relay for Testing
As mentioned above, the relay can be damaged when a loud click is heard occasionally whenever the compressor is warming up. However, the refrigerator start relay has to be removed from the system in order to have it checked. Before removing it from the system, make sure to unplug the unit first.
The relay is located at the rear bottom of the fridge. Simply remove the guard cover from at the back of the unit to expose the compressor. Near the compressor is a small box with wires coming out of it. This is the relay. Older units usually have a wire-wound relay that can be easily spotted because these units have a visible cooper wound around a plunger. Newer units are solid state relays that require special equipment for checking. These relays easily get fried, unlike the wire-wound relay.
Inspecting the Relay for Problems
If the relay has terminals that are badly corroded, it may need to be replaced. However, some relays just need to be cleaned in order to work again. Make use of a metal cleaner to remove the corrosion and place it back again. Try to check if this solves the problem. If the relay still does not work, then it may have probably burned out.
Checking for Bad Start Relays
There are a few methods to check whether the start relay is working fine or not. The solid state relays can be easily tested by removing it from the compressor and shaking it. If it creates a rattling sound, then it is indeed burned out. To make sure, have it checked by a professional.
For wire-wound relays, they can be checked using an ohmmeter. There are usually 3 terminals on the relay—2 usual terminals marked S and M and a slip-on terminal marked L. To check if the relay has continuity, place the 2 probes of the tester on the 2 terminals S and M. The reading should be zero. With the probe still touching the terminals, flip the relay over. This time, a click should be heard and the tester should read infinity. Do the same steps but with the probes touching the terminals S and L. The results should be the same. Do the same test with the probes on terminal M and L. This time, the reading should be zero even when it is flipped over. If not, replace the relay with a new one. Make sure to purchase the same type of relay from the supply store.