Mazda Haima S7/Knight Brake Light Switch A21-3720010, reliable shift safety warning light control

When your Mazda Premacy S7 or MX-5? (unclear) brake light is off, brake lights stay on, or the shift lever cannot release from P (with abnormal gear indicator), it usually indicates wear or poor contact of the original brake light switch. The switch, when functioning, accurately senses brake pedal action and synchronizes tail light illumination with the release of the shift lock solenoid, ensuring driving warnings and shifting safety. Fits OEM number 3720010 (factory part number A21-3720010) for Mazda Premacy S7 (2013–2016) and Mazda Axela/Verisa? (2010–2015). Installation requires disconnecting the battery negative, removing the old switch, then ensure the brake pedal is fully released before aligning the notch and rotating to fix, to avoid contact misalignment.