Abstract: A theft protection and alarm system for vehicles including a latching solenoid fuel cutoff valve, and a vibration and motion sensitive switch together with door, trunk and hood switches for actuating an audible alram. The alarm system is turned on and off by a novel key-operated switch. Conductors carried in electrical cables extending between the major components of the system normally energize a relay to maintain its contacts open. If one or more of the cables is cut, the contacts close sounding the alarm.