Abstract: This invention relates to an automatic alarm system for the discouragement of theft or unauthorized tampering with a so equipped motorcycle or other vehicle. This device consists of the motorcycle or vehicle's horn, lights, a source of electrical power (such as the vehicle's battery), an activating or "on" switch, a short circuit preventing fuse, an alarm limiting timer, and a circuit breaking triggering device held open by a non-conducting element of the motorcycle or vehicle which must be moved outside of the circuit breaking triggering device if the motorcycle or vehicle or its equipment is stolen or tampered with. A transmitter of limited range may be incorporated within the activated circuit for broadcasting a tone of identifiable character to interested persons should the circuit breaking triggering device be activated.