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Electrical

Starter Motor

The starter cranks the engine with a high-torque electric motor and pinion gear.

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Starting & charging flow

Interactive — tap a part
Battery Alternator Starter motor Ignition switch

Tap a part to see how it fits in the system.

What it does

  • Engages a pinion with the flywheel teeth
  • Spins the engine to starting speed
  • Disengages once the engine runs

When it fails

  • Clicking but no crank
  • Slow cranking
  • A whirring sound without the engine turning
  • Smell of burnt wire

How to diagnose

  1. Check battery voltage and terminals first
  2. Test the start signal at the solenoid
  3. Measure voltage drop during cranking
  4. Check the flywheel teeth for damage

Maintenance

  • Keep battery and ground connections clean
  • Fix charging faults early to protect the starter
Use the diagnosis order. When a part fails, confirm each hypothesis with measurements before replacing anything — codes and symptoms overlap.
Related part

Battery

The battery stores energy to crank the engine and powers the car when the alternator cannot.

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