Carautonomy — car parts and warning lights explained
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Electric Vehicles

What is an Electric Motor?

The single moving part that replaces the engine, gearbox and clutch.

ELECTRIC MOTOR — 3-PHASE AC SPINS THE ROTORINV3-phase ACstator + rotorwheelInverter switches DC into 3-phase AC → rotating magnetic field drags the rotor → wheels turn

Simplified animation — not to scale.

In plain English

In an EV, the electric motor is what spins the wheels. Most modern EVs use either a permanent-magnet synchronous motor (very efficient, common on rear axles) or an induction motor (cheaper magnets, often on front axles for AWD). Unlike a petrol engine with hundreds of moving parts, a typical EV motor has essentially one — the rotor.

A simple analogy

"It's like a giant cordless drill connected straight to the wheels. Press the trigger (accelerator), it spins. Release it, and you can spin it backwards to recharge the battery a little."

How it works

The inverter feeds the motor a rapidly switching three-phase AC current. This creates a rotating magnetic field in the stator, which drags the rotor (and the wheels) around with it. Change the frequency and the motor speeds up or slows down; change the direction and the car reverses — no gearbox needed. Lift off the accelerator and the motor runs in reverse as a generator, sending energy back to the battery (regenerative braking).

Signs of trouble

  • Whining or grinding noise from the drive unit
  • "Reduced power" warning
  • Vibration under acceleration
  • Loss of regen braking
  • Coolant leak around the motor housing
Rough UK cost

£2,400 – £9,200

Parts: £2,000 – £8,000
Labour: £400 – £1,200

Always get a written quote. Prices vary by car, region, and parts brand.

Heads up: Carautonomy is for general guidance only. If your car is showing warning lights or behaving oddly, get it looked at by a qualified mechanic.

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