Learning how to test a refrigerator starter relay is the fastest way to save a fridge that is clicking but not cooling. You walk into the kitchen and hear a loud “click,” followed by a buzz, and then silence. A few minutes later, it happens again.
That clicking sound is the #1 sign that this small, inexpensive part has failed. The starter relay is the “ignition key” for your compressor. If it dies, the compressor cannot start, and your fridge becomes a giant insulated box with no cooling. This is the most common reason for refrigerator making a clicking noise.
The good news? You do not need to call a pro. You can determine if the part is bad in less than 2 minutes.
In this guide, we will show you exactly how to test a refrigerator starter relay using two methods: the simple “Shake Test” and the professional “Multimeter Test.” While most relays are similar, the Whirlpool starter relay test is frequently searched because they often use a specific “PTC” relay that looks different.
Before You Learn How to Test a Refrigerator Starter Relay
Before you start pulling parts, it helps to know what you are looking for.
The compressor is the engine of your fridge. It requires a massive surge of electricity to start up, but very little energy to keep running. The starter relay (often combined with an overload protector) provides that initial jolt.
The Failure Symptoms
When this part fails, the compressor tries to start but can’t. You will notice:
- Clicking: A loud click every 2-5 minutes (the relay trying and failing).
- Warmth: The fridge and freezer are getting warm.
- Humming: You might hear a hum that abruptly stops.
If you have these symptoms, learning how to test a refrigerator starter relay can save you a $300 service call.
Safety First: Prep the Fridge
You are about to work with electrical components. Safety is non-negotiable.
- Unplug the Unit: Pull the plug from the wall. Never open the back panel while the fridge is plugged in.
- Access the Back: Pull the refrigerator away from the wall so you have room to work.
- Remove the Panel: Use a screwdriver to remove the cardboard or metal cover at the bottom back of the fridge.
Method 1: How to Test a Refrigerator Starter Relay by Shaking
This is the fastest way to diagnose the problem. You don’t need fancy tools to learn how to test a refrigerator starter relay; you just need your ears.
Step 1: Locate the Relay
Look at the large black tank (the compressor). On the side of the tank, you will see a small plastic box with wires connected to it. This is the start relay assembly.
Step 2: Remove the Relay
You may need to use a flathead screwdriver to pop off a wire retainer clip. Once the clip is gone, grip the plastic relay box and pull it straight off the three metal pins on the compressor. It might be tight, so wiggle it gently.
Step 3: Shake It
Hold the relay near your ear and shake it like a box of matches.
- If it rattles: It is bad. The internal components have shattered. Replace it immediately.
- If it is silent: It might still be good, or it might have a non-visible failure. Proceed to Method 2 to be sure.
Note: If the relay rattles, you have solved the mystery. You can order a new refrigerator starter relay and install it.
Method 2: How to Test a Refrigerator Starter Relay with a Multimeter
If the relay didn’t rattle, but you still suspect it is broken, you need to test the electrical continuity. This requires a digital multimeter.
Step 1: Set Up the Multimeter
Turn your multimeter dial to the lowest setting for Ohms of resistance (usually the 200 setting) or the “Continuity” setting (which beeps).
Step 2: Identify the Terminals
Look at the relay. You will see holes labeled “S” (Start), “M” (Run/Main), and “L” (Line). If they aren’t labeled, you are looking for the two holes that plug into the compressor pins.
Step 3: Test for Continuity
Place one probe into the “S” terminal and the other into the “M” terminal.
- Good Relay: The meter should read close to zero ohms (usually between 0.5 and 10 ohms). This means electricity can flow.
- Bad Relay: The meter reads “OL” (Open Loop) or infinity. This means the internal connection is broken.
If you get an “OL” reading, you have confirmed how to test a refrigerator starter relay failure electrically. The part is dead.
Step 4: Installing the New Relay
Once you have confirmed the part is bad, replacing it is the easy part.
- Buy the Part: Ensure you buy the specific relay for your model, or a high-quality “3-in-1” Hard Start Kit if you have an older fridge.
- Transfer Wires: Unplug the wires from the old relay and plug them into the exact same terminals on the new one.
- Push it On: Line up the holes with the three pins on the compressor and push it on firmly.
- Secure It: Replace the retaining clip if you have one.
Once installed, plug the fridge back in. You should hear the compressor hum to life instantly. If it starts cooling, you just saved your groceries.
What to Do After Learning How to Test a Refrigerator Starter Relay
If you learned how to test a refrigerator starter relay and it passed both tests (no rattle, good continuity), your problem lies elsewhere.
1. The Capacitor
Some fridges have a separate “Run Capacitor” attached to the relay. If this white cylinder is burnt or bulging, it needs replacement.
2. The Compressor
If the relay is good but the compressor still just “clicks” and gets hot without running, the compressor itself might be locked up. This is a major repair. Check our guide on refrigerator not cooling but running for more details on compressor failure.
3. The Main Board
If the compressor never even tries to start (no click, no sound), the main control board might not be sending power. See our guide on refrigerator not cooling after a power outage to check for board damage.
Frequently Asked Questions (FAQ)
1. Can I bypass the starter relay to test the compressor?
Technically yes, but it is dangerous and not recommended for DIYers. It involves using a “cheater cord” with live electricity. It is much safer and cheaper to simply buy a $15 relay to test it.
2. How much does a starter relay cost?
A standard OEM relay usually costs between $20 and $50. Generic “Hard Start” kits can be as cheap as $15. Compared to a $300 service call, this is a very cheap fix.
3. What causes a starter relay to fail?
Heat and age. The internal disk is made of ceramic and metal. Over years of heating up and cooling down, it becomes brittle and cracks. Dirty coils can also cause the compressor to draw more amps, burning out the relay faster. Make sure you know how to clean refrigerator coils to protect your new relay.
4. Will a bad relay cause the breaker to trip?
It can. If the relay shorts out, it can cause an electrical surge that trips your kitchen breaker or GFCI outlet.
Conclusion: Mastering How to Test a Refrigerator Starter Relay
Hearing that “click-buzz-click” is stressful, but now you know it is usually just a $20 plastic part.
Knowing how to test a refrigerator starter relay gives you the power to diagnose your fridge in minutes.
Your Action Plan:
- Unplug the fridge.
- Remove the relay.
- Shake it.
If it rattles, replace it. It is that simple.
