A repeating irregularity in a motor’s current can be useful evidence, but the load and drive method also influence the trace. An uneven pattern should not be labelled a failed commutator without context.

How to narrow it down

Compare the trace at a consistent operating condition and check whether the irregularity repeats with rotation or with the control command. Review supply stability and mechanical resistance. This makes the assessment more specific than judging a cropped waveform by appearance.

What to include with the fault report

Include the full operating cycle and whether the mechanism binds at a particular position.

Do not disassemble or energise a safety-related actuator outside the approved procedure to obtain a comparison.

Speak to AXION

For complex vehicle-electronics diagnostics, send your vehicle details and fault report. Workshop assessment is in Didcot, Oxfordshire. Suitable postal or remote work is confirmed before booking.

Technical background from STMicroelectronics. The referenced design explains the principle; the vehicle-specific procedure determines the repair.