Abstract: A high speed electric toy vehicle having a high current rating electric motor is provided with a fail-safe mechanism which would promptly operate to cut off motor power supply before the battery is burnt or the vehicle housing is melted as a result of over-current developed across an electric motor due to locking of rotary shaft under operating conditions. The fail-safe mechanism operates by detecting the presence or absence of motor motion as indicated by a motion tag which are attached to a part of the vehicle which always moves in response to movement of the motor shaft. The mechanism will cut off supply to the motor when no motion has been detected for a pre-determined time period.