Schumacher Audible Noise from Power Electronics or Contactor

Charger makes a high-pitched whining or buzzing noise during operation.

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Magnetostriction in transformer or inductors, Vibrating contactor coil, Loose mounting of power module, PWM switching noise

How to Fix / Troubleshooting

Safety first: Noise alone is not necessarily unsafe, but any accompanying smell, heat, or malfunction requires immediate shutdown.

  • Identify source: Listen closely to determine if the noise comes from the contactor area (clicking/buzzing) or the power module (steady whine).
  • Check mounting screws (qualified only): With power OFF, tighten mounting screws for the power module and contactor to reduce vibration.
  • Monitor operation: If the charger functions normally and temperatures are within spec, some noise may be normal.
  • If noise is new, loud, or accompanied by other symptoms: Have a technician inspect the contactor and power module for impending failure.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Power Module
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements