How to Test Voltage with a Multimeter on Your Washing Machine (Step-by-Step)

Your washing machine won’t start, the motor refuses to run, or the drain pump isn’t doing its job. You’ve checked the obvious things, but how do you know whether a component is actually bad or simply isn’t getting power? That’s where a multimeter comes in. Testing voltage helps you determine whether electricity is reaching the parts that need it, making it easier to narrow down electrical problems without replacing perfectly good components.

Most washing machines in the U.S. operate on 120 volts AC, and knowing how to measure that voltage can make a big difference when troubleshooting. A faulty outlet, damaged wiring, or malfunctioning control board can all interrupt power and cause symptoms that look like a failed motor or pump. Understanding voltage readings helps you separate electrical supply problems from component failures, saving time, money, and unnecessary repairs.

Because voltage testing involves live electricity, safety is especially important. Knowing when and where to test, how to use your multimeter correctly, and what the readings mean can help you make more informed repair decisions without taking unnecessary risks.

Full safety notes below

Safety First

Read this before you touch anything. You’ll be working with 120V AC household current, which can cause serious injury or death. Respect the electricity. If you’re not comfortable with any step, stop and ask questions on our forum before proceeding.

A few non-negotiable rules:

1. Never touch the metal tips of the multimeter probes with your fingers while testing a live circuit.

2. Hold probes by their insulated handles only.

3. Inspect your multimeter leads before every use; cracked insulation or exposed wire means replace them before testing.

4. Keep one hand free when probing live circuits. Don’t hold a probe in each hand while also touching the appliance chassis; this creates a path for current across your chest.

5. Work on a dry floor. Standing on a wet laundry room floor while probing a live outlet is asking for trouble.

6. If you’re testing parts off the machine (like a motor winding or a pump), unplug the washer first, disconnect the part, and then test it with the meter set to the appropriate function.

Tools and Materials

• Digital multimeter, any basic model works. A reliable meter from a hardware store is plenty.

• Probes: Your meter will come with a red and black test lead. Make sure the tips are sharp and the insulation is intact.

• Non-contact voltage tester (optional but handy), great for a quick check before you start poking around with probes.

• Flashlight or headlamp, washer wiring harnesses are usually crammed into dark spaces.

• Your washer’s wiring diagram is typically found inside the control panel or taped to the back/bottom of the machine. You’ll want this to identify which wires carry voltage to which parts.

How to Test Voltage with a Multimeter

Setting Up Your Multimeter

1. Insert the black probe lead into the port labeled COM (common ground).

2. Insert the red probe lead into the port labeled VΩmA or simply V. On most meters, there’s a separate port for high-amperage current; you do NOT want that one for voltage testing.

3. Turn the dial to AC voltage, look for the V\~ symbol or the V with a wavy line (\~) next to it. Household washers in the US run on 120V AC. Do not set the meter to DC (the V with a straight dashed line), you’ll get a zero reading and think there’s no power when there actually is, which is dangerous.

4. If your meter is manual-ranging, set it to the next range above the voltage you expect. For 120V, select the 200V range. If your meter is auto-ranging, just select AC voltage and the meter handles the rest.

Testing the Wall Outlet

Before you blame the washer, make sure the outlet is actually delivering power.

1. Insert the black probe into the taller (neutral) slot of the outlet.

2. Insert the red probe into the shorter (hot) slot.

3. Read the display. You should see somewhere between 108V and 132V; that’s the normal range for a 120V circuit. If you see 0V, the breaker may be tripped, the outlet is faulty, or the GFCI has tripped. Check your breaker panel and any GFCI outlets in the laundry area.

We see people skip this step all the time and go straight to tearing the washer apart, only to discover the outlet was dead the whole time. Always start here.

Testing Voltage at the Washer’s Power Cord

1. Pull the washer away from the wall enough to access the back panel. Unscrew and remove the rear panel or access cover to expose the wiring.

2. Plug the washer back in (yes, it needs to be live for a voltage test).

3. Locate where the power cord connects internally, usually a terminal block or wire nuts connecting the cord to the machine’s wiring harness.

4. Carefully place the black probe on the neutral (white) wire terminal and the red probe on the hot (black) wire terminal. You should see the same 120V reading as the outlet. If you get voltage at the outlet but not here, the power cord itself is bad.

Testing Voltage at a Specific Part

This is where things get really useful. Let’s say your washer fills with water but won’t agitate or spin; you want to know if the motor is getting voltage when it’s supposed to.

1. Locate the part you want to test. Find it on the wiring diagram so you know which wires feed it.

2. With the washer plugged in, select the cycle that should activate that part. For a motor, select a wash or spin cycle. For a drain pump, you need the machine in its drain phase.

3. Backprobe the connector, slide your probe tips along the back side of the wire connector to make contact with the metal terminals, without disconnecting anything. If you can’t backprobe, carefully disconnect the plug and probe the harness side (the side coming from the control board, not the part side).

4. Read the voltage. If you see 120V at the connector but the part isn’t running, the part itself is likely bad; the board is sending power, but the motor, pump, or valve isn’t responding. If you see 0V when the part should be active, the problem is upstream: a failed control board, broken wire, or bad connection.

This technique applies to virtually every electrical part in your washer: fill valves, lid switches, door locks, drain pumps, and motors. If you’re troubleshooting a specific part like a drain pump, our guide on how to test and replace the drain pump on a front-loading Whirlpool washer walks through the full process.

Common Mistakes to Avoid

Using the DC setting instead of AC. This is the most common beginner mistake. Your washer runs on AC current. The DC setting will give you a misleading near-zero reading on an outlet that’s fully energized. That false sense of security can get you hurt.

Testing with the washer unplugged. Voltage testing requires a live circuit. If you’re testing a disconnected part for functionality (like checking a motor winding), that’s a continuity or resistance test, a different procedure entirely. For voltage, the power must be on.

Probing the wrong terminals. Washer connectors can have multiple pins. If you probe the wrong two, you might read 0V and incorrectly condemn a good control board. Always reference your wiring diagram. It’s right there on the machine; use it.

Ignoring intermittent connections. A corroded or loose wire terminal might read 120V with no load but drop to almost nothing under load when the part tries to draw current. If your readings look fine but the part still isn’t working, wiggle the connectors while watching the meter. A flickering reading points to a bad connection.

How to Verify Your Results

A successful voltage test gives you a clear answer: either power is present at the expected level, or it isn’t. Here’s how to know you did it right:

• At the outlet: 108–132V AC means normal power.

• At a part connector during the correct cycle phase, 120V AC means the control board and wiring are doing their job. The part is the suspect.

• 0V at a part that should be energized: The fault is in the wiring, a switch, a relay on the control board, or the board itself.

• Fluctuating or abnormally low readings (under 100V): Could indicate a loose connection, damaged wire, or even a house wiring issue.

Once you’ve identified a failed part through voltage testing, grab your model number and find the exact part for your model to get the right replacement shipped to your door.

Need More Help?

Every washer is a little different, and wiring harness layouts can vary between brands and even model years. If you’re staring at a connector and can’t figure out which pins to test, or your readings don’t match what you expected, post your question, along with your model number and the readings you’re getting, on our repair forum. We’ll help you figure out the next step.

If you need any replacement parts for your appliances, you can enter your model number at AppliancePartsPros.com to locate and order them quickly. Most orders arrive in just two business days, and we have tons of great information in our repair help section and YouTube videos to help you troubleshoot.

Stay connected with the latest DIY tips, tutorial videos, and repair guides by following us on Facebook, Instagram, and Twitter. We love hearing about your repair stories and successes. If you need more help or want personalized guidance, feel free to contact or call us at 877-477-7278. We’re ready to help you take on your next project with confidence!

Since 1999, AppliancePartsPros.com has helped millions of people repair their broken appliances by providing high-quality original parts at well below retail prices, free support and troubleshooting, and award-winning customer service from an expert, friendly customer support team!

Written by: AppliancePartsPros Team