Okay, that's a frustrating problem. The fact that it's only happening on the same phase as the washer, and only during agitation, points to a voltage drop/sag specifically on that leg of your electrical system. Since you've already checked the obvious connections at the panel and the receptacle, here's a more comprehensive troubleshooting approach, broken down by potential cause and where to check

I. Problems WITHIN the Washer (Less Likely, but Possible)
Worn Motor Brushes (if applicable)

Some older washers use brushed motors. Worn brushes can create arcing and cause voltage fluctuations.

How to check

Listen closely to the motor during agitation. Excessive sparking sounds could indicate bad brushes. Access and visually inspect the brushes (you may need to consult your washer's service manual). Replacement brushes are often available.

Intermittent Wiring within the Washer

A wire partially broken or a loose connection inside the washer could cause a sudden load change.

How to check

Disconnect the washer from power FIRST. Carefully inspect all wiring connections inside the washer, paying close attention to the motor, timer/control board, and any heating element (if it's a hot water fill washer). Look for discoloration, melted insulation, or loose connectors. Gently tug on wires to see if they are securely connected.

Pump motor The pump motor is another element that runs during the agitation process. A dying pump motor could be causing an issue when it comes on. How to check Listen to the pump motor during agitation. Does it sound like it is struggling? Are there any loud or unusual noises?II. Problems in the Branch Circuit Wiring (More Likely)

This is where voltage drop is the most probable cause Loose Neutral Connection (MOST COMMON CAUSE)

A loose neutral is a very common cause of flickering lights and other electrical oddities. It's a serious safety hazard. The neutral carries the return current. If the neutral connection is weak, the voltage on that leg can fluctuate dramatically as the load changes.

How to check



At the Washer Outlet

Even though you replaced it, re-check that the neutral wire is securely connected to the outlet. Make sure the wire is fully inserted into the connector and the screw is tightened firmly (but not so tight you strip it).

In Junction Boxes Along the Circuit

Trace the circuit backwards from the washer outlet towards the panel. Look for any junction boxes along the way (often in the basement, attic, or crawlspace). Turn off the breaker before opening any junction box. Check the neutral connections (usually white wires). Look for loose wire nuts, push-in connectors that might not be making good contact, or wires that are corroded. If you find suspect connections, replace the wire nuts or connectors.

In the Panel (Again, but Specifically the Neutral Bar)

Re-check the neutral connections in the panel. Turn off the main breaker before working inside the panel. Ensure the neutral wire for the washer circuit is securely connected to the neutral bar. Look for signs of corrosion or overheating.

Loose Hot (Black) Wire Connection

Although less likely than a loose neutral, a loose hot wire connection can still cause problems. Check all hot wire connections along the circuit, from the washer outlet back to the breaker in the panel.

Undersized Wiring

If the wiring gauge for the washer circuit is too small for the load, it can cause a voltage drop under heavy load. This is more likely in older homes where wiring standards might have been different.

How to check

Look at the wire gauge (AWG) printed on the cable sheathing. For a standard 120V, 20A washer circuit, you should ideally have 12 AWG wire (or larger – 10 AWG is even better). If it's 14 AWG, that could be the problem, but don't attempt to replace wiring yourself if you're not comfortable with electrical work. This would require rewiring the entire circuit.

Long Wire Run

A very long wire run from the panel to the washer outlet can also contribute to voltage drop. This is especially true if the wire gauge is already borderline.

Shared Neutral (Multi-Wire Branch Circuit Issues)

In some older homes, two circuits might share a single neutral wire. If the loads on both circuits are unbalanced, it can cause voltage fluctuations.

How to check

This is a more complex issue to diagnose. You'll need to trace the wiring back to the panel and see if two breakers are connected to the same neutral wire. This is something best left to a qualified electrician.

III. Problems at the Service Entrance/Main Panel (Less Likely, but Serious)

If the problem persists after checking all the branch circuit wiring, the issue might be at the service entrance or main panel. This is where you should seriously consider calling an electrician. Loose Connections at the Main Breaker or Service Entrance

Loose connections at the main breaker, the meter socket, or where the service wires enter the house can cause widespread voltage fluctuations. These are extremely dangerous to work on and should only be addressed by a qualified electrician.



Corroded or Damaged Service Entrance Cables

Corrosion or damage to the service entrance cables can restrict current flow and cause voltage drops.

Problems with the Utility Company's Transformer or Wiring

In rare cases, the problem might be with the utility company's equipment. If you suspect this, contact your utility company.

Troubleshooting Tips & Safety Precautions



Turn off the breaker before working on any electrical wiring.

Use a voltage tester to confirm that the power is off before touching any wires.

If you're not comfortable working with electrical wiring, call a qualified electrician.

Take pictures before disconnecting any wires, so you can remember how they were connected.

When tightening screws, make them snug, but don't overtighten them, as this can strip the threads.

If you find any signs of burning, melting, or corrosion, replace the affected components.

Test the washer circuit after making any repairs to ensure that the problem is resolved.

Use a multimeter to measure the voltage at the washer outlet while the washer is running. A significant voltage drop during agitation indicates a wiring problem.

Document everything you do. Note the date, time, what you checked, and what you found. This will help you (or an electrician) track down the problem.

In Summary (Steps to Take)


Start with the washer itself

Check motor brushes, wiring, and pump motor.2.

Focus on the neutral connections

Check the neutral wire at the washer outlet, in junction boxes, and in the panel.3.

Check hot wire connections.4.

Inspect the wire gauge

Is it adequate for the load?5.

Consider a long wire run.6.

If the problem persists, call a qualified electrician to inspect the service entrance and main panel.*Good luck! Be patient and methodical, and remember that safety is paramount. Flag for review