Well Pump Electrical Troubleshooting

Start at the Breaker

Check whether the breaker is tripped, and if so, reset it once. If it trips again immediately, stop — that indicates a short circuit or a locked motor, and further breaker resets risk damaging wiring or the panel. If it holds after one reset but trips again later under load, that points to an overloaded circuit or a motor drawing excess current.

Check the Pressure Switch

With power on, use a multimeter to check for incoming voltage at the pressure switch (should read your standard 230V, or 115V on some smaller systems). If voltage is present at the switch but not passing through to the pump wiring, the switch contacts themselves have likely failed or are dirty enough to prevent proper contact.

• No voltage at the switch at all — problem is upstream, at the breaker or panel wiring
• Voltage in but not out — switch itself has failed
• Voltage passes through fine — problem is downstream, at the control box or pump

Check the Control Box (3-Wire Systems Only)

If voltage reaches the control box but the pump still doesn't respond, the capacitor or relay inside the box is the next suspect — see our dedicated guides on capacitor symptoms and relay vs. capacitor diagnosis for the next steps.

Ruling Out the Pump Itself

If voltage checks out all the way to the pump's wiring and the motor still won't run, a megohmmeter (megger) test on the motor windings can reveal a grounded or shorted winding — this is typically a job for a well pump professional, since it usually means pulling the pump for replacement.

Know Whether You Have a 2-Wire or 3-Wire System First

This matters before you start testing, because it changes where the likely failure point is. A 2-wire pump has all starting components (capacitor and relay equivalent) built into the motor itself, submerged in the well — there's no separate control box to check, which means fewer external parts can fail but also means a motor-level fault is your only real electrical suspect once wiring and the pressure switch check out. A 3-wire pump has those components in an above-ground control box, giving you more accessible parts to test (and replace cheaply) before concluding the motor itself has failed. You can tell which you have by checking your pump's data plate or looking for a control box near the pressure tank — if there's no separate box, it's a 2-wire system.

Tools You Actually Need for This

A basic digital multimeter capable of reading AC voltage and resistance/continuity covers the vast majority of the steps above and typically costs $20-$40. A clamp meter that reads amperage is a useful add for comparing actual draw against the pump's rated nameplate current, which helps confirm a capacitor or winding problem versus a wiring issue. A megohmmeter (megger), used specifically to test motor winding insulation, is a specialized tool most homeowners won't own — this is the point where it usually makes sense to call in a professional rather than buy single-use equipment.

When a Megger Test Is Worth Paying For

A megger test typically costs $75-$150 as part of a service call, and it gives a definitive answer on whether the motor windings themselves have failed versus every component upstream being fine. Given that a full pump replacement runs $800-$2,500+, spending $75-$150 to confirm the motor is actually the problem — rather than guessing and pulling a pump that turns out to be fine — is generally worth it whenever you've ruled out the breaker, switch, and control box but the pump still won't run.

Frequently Asked Questions

Is it safe to test well pump wiring myself?

Basic voltage checks with a multimeter are manageable for many DIYers, but always treat the circuit as live and take proper precautions. If you're not confident, hire a licensed electrician.

Why does my breaker trip immediately every time I reset it?

This usually indicates a short circuit or a locked (seized) motor. Continuing to reset the breaker can cause further damage — have it diagnosed before resetting again.

Can a bad pressure switch look exactly like a dead pump?

Yes — a pressure switch with failed contacts will show no power reaching the pump even though everything upstream and downstream is fine.