An EWP's electrical system does more than start the engine and light the panel — it runs the controls, drives the safety interlocks and, on many machines, manages tilt, overload and emergency functions. An electrical fault can therefore be as minor as a flickering indicator or as serious as a safety device that no longer intervenes when it should. Because so much of a modern access machine's protection is electrical, a fault in the wrong circuit is not an inconvenience to work around; it is a reason the machine should not be used. This guide walks through how electrical faults present, what tends to cause them and why the safety circuits get special treatment.
How electrical faults present
Electrical problems on an EWP show up in a range of ways:
- Intermittent or unresponsive controls — functions that work sometimes, respond slowly, or need the joystick worked to react.
- A safety device that fails to operate — a tilt alarm, overload cut-out or interlock that no longer stops or limits the machine as intended.
- Fault codes or warning lights on machines with electronic control systems, flagging a sensor, circuit or module problem.
- Batteries that will not hold charge, or a machine that is flat after standing, pointing to charging or parasitic-drain faults.
- Corroded, green or crusty connectors and terminals, or chafed and damaged wiring found on inspection.
What causes them
- Water and moisture ingress into connectors, switches and control boxes, which corrodes contacts and causes intermittent faults.
- Vibration, which loosens terminals, fatigues wiring and chafes looms against structure until the insulation wears through.
- Corroded connectors and earth points, a very common source of the intermittent gremlins that are hard to chase down.
- Failed sensors, switches or solenoids in the control and safety circuits.
- Damaged wiring from crushing, abrasion, rodents or poorly executed past repairs.
How faults are diagnosed
Electrical diagnosis on an EWP is systematic work, not guesswork. A technician uses the machine's wiring diagrams, reads any fault codes the control system reports, and works methodically through the circuit with a multimeter to find where voltage, continuity or a signal is being lost.
The safety circuits get particular attention because they are the machine's protection. Interlocks, the emergency lowering function, tilt and overload systems and the emergency stop are all function tested to confirm they respond exactly as intended — the same devices an operator proves during a pre-start, verified in more depth by a competent person. A safety device that does not test correctly is a defect that takes the machine out of service.
How electrical faults are put right
- Isolate the machine safely before working on the circuit.
- Repair to the source — renew the failed sensor, switch, solenoid or wiring, and clean and protect corroded connectors and earths.
- Use correct connectors, terminals and cable, sealed and routed to keep water and abrasion out, rather than a temporary bodge.
- Restore any safety-related setting or calibration to the manufacturer's specification.
- Function test every affected control and safety device before the machine returns to service, and record the work.
Preventing electrical trouble
Most electrical faults trace back to water and vibration, so the prevention is about keeping those out. Keeping control boxes and connectors sealed and dry, protecting looms from chafing, and cleaning and protecting earth points and terminals heads off the intermittent faults that are the hardest to find.
Faults in the safety circuits are never something to run through. If an interlock, tilt system, overload device or emergency function does not behave correctly, the machine should be taken out of service and referred to a competent person — you can reach EWP Australia on 0416 689 689 to arrange it.
This guide is general information prepared by EWP Australia and is grounded in publicly available Australian Standards and Safe Work Australia material. It is not a substitute for the current published edition of the relevant standard or for site-specific engineering advice. Always work from the current standard and consult a competent person for your specific equipment and application.