Check if the engine starts when the clutch pedal is fully depressed and doesn't start when released. If it doesn't follow this, disconnect the clutch switch near the top of the pedal. Test continuity between connector terminals when the pedal is depressed. If there's continuity, the switch is fine; if not, replace it. If there's continuity when the pedal is released, also replace the switch. Remove the switch by loosening the locknut and unscrewing it from the bracket. Install by reversing these steps. Adjust the switch by turning it in or out to ensure continuity when the pedal is depressed.