That clicking sound with no cooling is almost always a failed start relay. The fridge tries to start the compressor, the relay can’t do its job, the compressor shuts off, and the cycle repeats every few minutes. Most of the time this is an inexpensive part and a straightforward fix.
What’s Actually Happening
The compressor needs a quick jolt of current to get spinning. The start relay delivers that jolt. When the relay fails, it clicks (or rattles), the compressor never turns over, and the fridge just sits there getting warm while making that maddening sound every few minutes.
There’s also a thermal overload protector, a separate safety device that cuts power if the compressor overheats. A bad overload can cause the same clicking pattern. Less common than a bad relay, but worth knowing about.
Compressor failure itself is a different scenario. It’s possible, but it’s the last thing you want to assume because a compressor is expensive. The clicking pattern actually gives you reason for hope, not despair. A completely dead compressor usually doesn’t click at all. If it’s clicking, the electrical side is still trying, and the relay is the most likely weak link.
How to Check the Start Relay Yourself
This is one of the few fridge repairs that’s genuinely safe and simple for a homeowner. You’ll need to pull the fridge out and access the compressor, which is at the back near the bottom.
Pull the power cord first.
The relay is a small plastic component that plugs directly onto the side of the compressor. It usually pops off with a firm pull, no tools needed. Once you have it in your hand, shake it. If you hear something rattling inside, the relay is bad. No rattle doesn’t guarantee it’s good, but a rattle is a clear answer.
You can also test it with a multimeter. Set it to ohms or continuity mode, then put the probes on the two terminals (the start and run terminals that plug onto the compressor pins). A good relay will show near-zero resistance or a continuity beep. An open circuit reading (OL or infinite resistance) means it’s failed.
Replacement relays are widely available by searching your fridge’s model number (usually on a sticker inside the door). Part prices vary by brand and model, so check before assuming, and get a quote rather than going in blind.
One note: some relays come as a combined relay-and-overload unit. If yours is one piece, you replace the whole thing together.
What a Tech Checks Beyond the Relay
If a new relay doesn’t fix it, the next step is the overload protector. Same general area on the compressor. A tech will test it for continuity and check that its resistance is within spec.
After that, we get into compressor diagnostics. The tech will check the compressor windings with a multimeter, measuring resistance across the common, start, and run terminals. Readings that are way off spec, or an open circuit in the windings, indicate a failed compressor. We also check whether the compressor is shorted to the case, which is another sign of failure.
The start capacitor (if the model has one) is also on the checklist. A weak or failed capacitor can prevent the compressor from starting even if the relay and overload are fine.
Refrigerant level is usually not the cause of clicking with no start, but if the system is low enough it can trigger pressure switches and strange behavior. That diagnosis requires gauges and a licensed tech.
DIY-Safe vs. Call a Pro
Safe to DIY: Testing and replacing the start relay, and testing or replacing the overload protector. These involve low-voltage connections, no refrigerants, and no special tools beyond a basic multimeter if you want to test rather than just swap.
Call a pro: Anything involving the compressor itself, refrigerant, the sealed system, or the main control board. Compressor replacement is a major job and the economics usually don’t work unless the fridge is relatively new and high-value. A tech can give you an honest read on whether repair makes sense versus replacement.
If you replace the relay and the fridge still won’t start, don’t keep throwing parts at it. Get a proper diagnosis. A good tech will tell you straight whether the repair is worth it.
When to Call a Pro
If the relay swap doesn’t fix it, call someone. Not because the subsequent steps are dangerous, but because compressor diagnostics require tools and experience to interpret correctly. Guessing wrong is expensive.
Also call a pro if you’re not comfortable pulling the fridge out and handling the back panel. There’s no shame in that. The relay is the one thing a reasonably handy homeowner can handle; everything downstream is better left to someone with the right tools.
If you’re in the Tri-Valley or East Bay, we handle this kind of diagnosis regularly. We can usually be out same or next day. You can book at adriumservice.com.
One honest note: if a tech tells you the compressor is gone on a fridge that’s more than 10 to 12 years old, get a second opinion before authorizing the repair. Compressor replacement on an older unit often costs more than a replacement fridge. A straight-shooting tech will tell you that upfront.