Linear Actuator Not Working? A Step-by-Step Troubleshooting Checklist

A linear actuator that will not move is usually not broken. In most cases the cause is in the power, the wiring, the controller, or the mechanism around it — and it can be found in ten minutes with a methodical check. Work through this list in order, and do not skip ahead: each step rules out one cause before you move to the next.

Before You Start: Two Safety Rules

1. Disconnect power before you touch wiring. Do not rewire, swap leads, or tighten terminals with the supply live.
2. If you smell burning, see smoke, or the motor is too hot to touch, stop. Disconnect power, let it cool, and do not keep cycling it to “see if it clears.” Repeatedly forcing a stalled, overheating motor can damage it permanently. See “When to Stop” at the end.

You will need: the actuator’s product page (Full Specifications), a multimeter if you have one, and the supply and controller you actually installed — not the ones you meant to install.

Step 1: Is There Power at All?

Symptom: nothing happens, no sound, no movement in either direction.

• Check the supply is plugged in, switched on, and set to the right output (12V or 24V to match your actuator).
• Check the fuse or breaker in the circuit. A blown fuse is a symptom, not just a fault: note it, replace it once, and if it blows again, stop and look for a short or a jam (Step 6) rather than fitting a bigger fuse.
• If you have a multimeter, measure the voltage at the supply output terminals, then again at the actuator leads. Voltage at the supply but not at the actuator means the break is in the wiring or the switch in between.
• If the supply has an indicator light or a reset button, check both. Some supplies shut down on overcurrent and need a power cycle to reset — but if it trips again under load, the supply is undersized or the actuator is jammed (Step 8).

Step 2: Is the Voltage Right?

Symptom: the actuator moves weakly, slowly, or not at all; or it ran once and then stopped.

• A 24V actuator on a 12V supply will run weak or not at all. A 12V actuator on a 24V supply is over-driven and can overheat. Check the model you bought against the supply label — do not go by memory.
• Check the voltage under load, if you can. A supply that reads fine with nothing connected but sags badly when the actuator starts is either undersized or failing. Compare its continuous current rating with the table in Step 8.

Step 3: Is the Polarity Correct?

Symptom: the actuator moves, but in the opposite direction from the switch labels — or it moves one way and not the other.

• A DC actuator reverses by swapping its two leads. If “extend” retracts and “retract” extends, swap the two actuator leads (with power off) and test again.
• If it moves one way but not the other, the fault is usually in the switch or controller (Step 4), not the actuator: one direction’s contacts or one output of the controller may have failed. Test the actuator directly on a known-good supply, both polarities, to separate the actuator from the controller.

Step 4: Is the Controller or Remote the Problem?

Symptom: the actuator works when wired directly to a supply, but not through the switch, controller, or remote.

• Test the actuator direct first: supply to actuator, both polarities, with power off while you connect. If it runs both ways direct, the actuator is fine and the fault is upstream.
• For a rocker switch: check both directions, and check for loose or corroded terminals.
• For a wired controller: check the handset connection and the control box input. Check whether the kit’s own adapter is in the chain — HyHaven’s Wired Controller Kit in its 24V version outputs 24V DC at 2.5 A, which covers small actuators (U1, U2) but not larger ones. A larger actuator fed through that adapter will stall or trip even though the main supply is fine.
• For a wireless remote: check the receiver’s power and its pairing with the handset, and check for a flat handset battery before suspecting the receiver. Keep the handset close for the test — distance and interference are easy to rule out by standing next to the receiver, and we do not quote a remote range figure because it depends on the installation.
• For any controller: confirm its current rating covers the actuator’s full-load current. A controller is a bottleneck like any other part of the circuit.

Step 5: Is the Wiring Sound?

Symptom: intermittent movement, movement that stops when you wiggle a wire, or one direction working and the other not.

• Inspect every joint: loose terminals, wires pulled half out of crimps, and corrosion at outdoor or damp connections are the usual suspects.
• Look for damaged insulation, pinched wires at hinges or moving parts, and wires that flex every cycle until they break inside the insulation. A wire that looks fine outside can be broken inside at a bend point.
• Check wire length and thickness qualitatively: a long, thin run drops voltage, especially at 12V. If the actuator runs fine on a short test lead but not on the installed run, the installed wiring is the suspect. Re-route shorter or thicker rather than raising the voltage to compensate.
• Re-check your wiring against our wiring guide, especially the reversing connections. A single swapped lead in a rocker-switch or controller circuit produces exactly the “one direction only” symptom.

Step 6: Is Something Jammed or Binding?

Symptom: the actuator hums, strains, or moves a little and then stops; or it ran fine unloaded on the bench but stalls installed.

• Disconnect the actuator from the load if you safely can, and run it unloaded. If it runs freely unloaded but stalls under load, the problem is mechanical: binding, misalignment, or overload — not the motor.
• Move the mechanism by hand through its full travel. Feel for tight spots, scraping, or a hinge that catches at one point. Guides, slides, and pivots all need to move freely through the whole range, not just at rest.
• Check the mounting geometry: a push that is off-centre, or brackets that force the actuator sideways as the load moves, will bind. The actuator should push along its own axis, with guides carrying any sideways load.
• Check for obstructions added since installation: a cable caught in the travel, a panel fitted after the actuator, ice or debris in an outdoor mechanism. Clear the path and retest before suspecting the actuator.

Step 7: Has It Reached a Limit?

Symptom: the actuator moves one way but not the other, and it is at one end of its travel.

• HyHaven actuators have built-in limit switches that stop the motor automatically at both ends of the stroke. This is normal behaviour, not a fault: at full extension it will not extend further, and at full retraction it will not retract further.
• If it will not move in either direction while mid-travel, it is not the limit switches — go back to Steps 1, 4, and 6.
• If the actuator stops short of where the mechanism needs to go, the stroke or the bracket geometry is wrong, not the limit switch. See our stroke measurement guide before moving brackets or ordering a different stroke.

Step 8: Is the Supply Big Enough for the Load?

Symptom: the actuator moves unloaded but stalls, crawls, or trips the supply under load.

Size everything for full-load current, not no-load current. Verified full-load currents:

If the supply, controller, switch, or fuse in the chain is rated below the actuator’s full-load current, that part is the bottleneck even when everything else is fine. Check each link, not just the supply. Also check the load itself: if the real load exceeds the actuator’s force rating, no supply will fix it — re-weigh the load and check it against the force rating with margin. A related check: if the actuator stalls only at the hardest point of the travel (the start of a lift, the tightest point of a hinge), the load at that point may be higher than the average load. Geometry, not the motor, is usually the fix.

Step 9: Is It Overheating from Continuous Use?

Symptom: the actuator works for a while, then stops, then works again after cooling down.

• DC actuator motors are not designed for non-stop cycling without rest. If your application runs the actuator back and forth continuously, heat builds up and performance drops.
• Let the motor cool fully, then test a single cycle. If a single cycle is fine but repeated cycling fails, the duty pattern — not a single fault — is the issue. Reduce the cycling rate, give rest time between cycles, or reconsider whether the application needs a different drive arrangement.
• Do not defeat a thermal cut-out or fit a bigger fuse to force a hot motor to keep running. That trades a recoverable stop for permanent damage.

Quick Symptom Table

When to Stop and Ask for Help

Stop troubleshooting and contact support if you find any of these:

• Burning smell, smoke, melted insulation, or discoloured terminals.
• A fuse that blows again immediately after replacement.
• A motor too hot to touch after a single short cycle.
• Visible damage to the actuator body, rod, or cable.
• The actuator ran fine, then failed suddenly with no wiring or load change, and Steps 1–6 all check out.

When you contact support, include: the model, the voltage, the supply rating, the controller type, what the actuator does (nothing / one direction / stalls under load), and at which step of this checklist the behaviour changed. That information shortens the diagnosis from days to a single exchange.

FAQ

My actuator worked yesterday and does nothing today. Where do I start? Power and fuse first (Step 1), then the controller (Step 4). Overnight failures are usually a tripped supply, a blown fuse, or a connection that worked loose — not a motor that died quietly.

It clicks but does not move. Is the motor dead? Not necessarily. A click with no movement often means the supply or controller is tripping on overcurrent — which points to a jam or an overload (Steps 6 and 8). Check the mechanism by hand before condemning the motor.

Can I test the actuator without the controller? Yes: wire it directly to a correctly rated DC supply, both polarities, with power off while you connect. This single test separates actuator faults from controller faults, and it is the most useful test in this whole guide.

Should I open the actuator to look inside? No. Opening the housing will not help a field diagnosis and can damage the seals, the limit switches, and the gearing. Work through the external checks in this guide, then contact support with the results.

How do I know whether it is the supply or the actuator? Swap one variable at a time. A known-good supply on the suspect actuator, or the suspect supply on a known-good load, tells you which side the fault is on. Guessing at both at once tells you nothing.

The Short Version

Test in order: power, voltage, polarity, controller, wiring, mechanism, limits, supply size, heat. Test the actuator direct to separate it from the controller. And never force a hot, smoking, or repeatedly fuse-blowing actuator to keep going — that is how a small fault becomes a dead motor.

For the electrical side, read our power supply sizing guide and our guide to wiring a linear actuator. For the geometry side, see our stroke measurement guide, and browse controllers and remote kits if the controller turns out to be the bottleneck.