How to Check a Refrigerator Compressor Relay With a Multimeter

How to Check a Refrigerator Compressor Relay With a Multimeter

ByKen

How to Check a Refrigerator Compressor Relay With a Multimeter

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The person typing how to check a refrigerator compressor relay with a multimeter wants to know whether the start relay is why the compressor will not run or keeps clicking. The direct answer: unplug the refrigerator, remove the relay from its socket, and use a multimeter in continuity or ohms mode to check the contacts and, where the relay has a coil, the coil. A single meter check tells you whether the parts show an open or closed path. It does not confirm the compressor or the start circuit as a whole.

Safety first

A refrigerator compressor circuit runs on mains voltage. Unplug the refrigerator from the wall outlet, or switch off its breaker, before you remove the back panel or touch any relay terminal. Fluke’s continuity guide says to always unplug the device or turn off the main circuit breaker before a continuity test, and to make sure any capacitors are safely discharged. Compressors can also have a start capacitor that stores charge, so treat that part as live until it is discharged by a qualified person. If you are unsure, call an appliance technician.

Quick answer

  • Unplug the refrigerator and confirm no power is reaching the relay before you touch it.
  • Remove the relay from its socket and photograph the wiring so you can reinstall it the same way.
  • Check the relay’s contact pins in continuity mode. Open contacts that never close point to a relay fault.
  • If the relay has a coil, measure the coil terminals in ohms mode. An OL reading on the coil points to an open coil.
  • The sources we opened do not give a resistance value for a compressor relay, so compare with the marking on the relay or your model’s service data.

How we chose

This guide covers two meter checks on a refrigerator compressor relay: contact continuity and coil resistance. We read three Fluke pages on continuity and fuse testing on 2026-10-27 and used their general method: de-energized component, isolated test, meter self-check, and reading interpretation. We did not find a source that describes refrigerator compressor relays, their coil values or their switching behavior. We considered only multimeter checks and left out compressor, capacitor and overload protector diagnosis.

What you need

  • A digital multimeter with continuity and ohms settings.
  • Test leads with the black lead in COM and the red lead in the VΩ jack.
  • Basic hand tools to reach the back panel and the relay.
  • The relay’s printed markings or part number, and your model number.

Step 1: Unplug and expose the relay

Unplug the refrigerator and wait before you open the back panel. Locate the relay on the compressor’s electrical box. Take a photo of the terminals and the wiring before you remove any wire. Mark each wire if you can, because a reversed connection can cause a fault when the unit is restarted.

Step 2: Remove the relay

Remove the relay from its socket or disconnect its terminals as the service information describes. Testing a relay while it is still wired into the circuit can give a misleading reading, because other conductors may complete a path. Fluke’s continuity guide says the component should be isolated from other components in the circuit so the reading reflects that component.

Step 3: Check the meter

Set the meter to continuity mode and touch the probes together. The meter should beep. Fluke’s fuse guide recommends this check because it confirms the meter works before you test the relay. If the meter does not beep, check the leads and battery first.

Step 4: Test the contacts

Place the probes on the two contact pins that the relay uses to switch power to the compressor. Note whether the meter beeps or shows OL. Many relays have contacts that are open when the relay is de-energized, so an OL reading on the contacts can be normal when the relay is at rest. Check the relay’s markings or your service data to confirm which pins are the normal-open contacts before you judge the result.

Step 5: Test the coil

If the relay has a coil, set the meter to the lowest ohms range that will show the coil resistance, and place the probes on the two coil terminals. Fluke’s continuity guide says a low resistance on a component that should have low resistance is a sign of a closed path, and an OL reading means the path is open. A coil that reads OL is a likely fault. A coil that reads a number is not automatically good, because the value has to match the relay’s specification.

Step 6: Read the results

Fluke’s continuity guide says a meter beeps when it detects a complete path, and that the resistance needed to trigger the beep varies by meter. Its explainer says most meters indicate continuity between 0 and 50 ohms. On a 400.0 Ω range, Fluke’s guide gives 40 Ω or less as an example of when a meter typically beeps. Check your meter’s manual for its exact threshold.

  • Contacts beep when they should be closed: the contacts are conducting in that state.
  • Contacts show OL when they should be open: this may be normal. Confirm against the relay markings.
  • Coil shows OL: the coil path is open. Replace the relay after confirming the part number.
  • Coil shows a number: record the value and compare it with the relay specification. The sources we opened do not give a figure for this part.

Step 7: Reinstall and check the unit

Turn the meter off, reconnect the relay in the same order as your photo, and reinstall the panel. Plug the refrigerator back in and listen for the compressor. If the compressor still does not start, the relay may be fine and the fault may lie in the start capacitor, the overload protector, the thermostat or the wiring. Those checks belong to a qualified technician.

Common mistakes to avoid

  • Testing with the power on. Fluke says continuity testing should be done only when voltage is not present.
  • Leaving the relay wired in. This can give a reading that does not come from the relay alone.
  • Reading OL on the contacts and assuming a fault without checking which state is normal.
  • Skipping the capacitor warning. A start capacitor can hold a charge after the unit is unplugged.

What we could not verify

  • The coil resistance or contact rating of any compressor relay. The sources we opened do not list these figures.
  • The start sequence, timing and failure symptoms of a particular compressor. These are not in the sources we opened.
  • Whether a given relay is the right replacement for your model. Match the part number on the relay with your service data.

FAQ

Can I test the relay without removing it?

An isolated test is more reliable. Testing in the circuit can include other paths, so remove the relay or disconnect it as your service information describes.

Why does the relay click but the compressor does not start?

A clicking relay shows that the coil is energized, but it does not prove the contacts close under load. The start capacitor, the overload protector or the compressor may be at fault. Those parts need separate checks.

What does OL mean on a relay coil?

OL means the meter sees an open path or a value above its range. On an isolated coil, that points to an open coil.

Can I replace the relay with any relay of the same look?

No. Match the part number, the coil voltage and the contact rating from the markings or the service data for your model.

Is it safe to test a relay myself?

A continuity and coil check with the unit unplugged is a basic task for a trained person. Working near the compressor and its capacitor needs training. If you are not sure, call a technician.

Bottom line

Unplug the refrigerator, isolate the relay, and check the contacts and coil in continuity or ohms mode. An open coil is a strong sign of a fault. Contact results depend on which state is normal, so check the markings before you decide.

Related guides

Sources

  • Fluke, “A Guide to Continuity Testing with a Multimeter”, https://www.fluke.com/en-us/learn/blog/digital-multimeters/how-to-test-for-continuity (opened 2026-10-27)
  • Fluke, “What is Continuity?”, https://www.fluke.com/en-us/learn/blog/electrical/what-is-continuity (opened 2026-10-27)
  • Fluke, “How to Check a Fuse with a Multimeter”, https://www.fluke.com/en-us/learn/blog/digital-multimeters/how-to-check-fuse-with-multimeter (opened 2026-10-27)

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