Abstract: A security and alarm system for vehicles includes a portable receiving unit with a remote alarm therein and a transmitter unit physically placed with a vehicle. The transmitter unit broadcasts a continuous radio frequency signal received by the receiver unit. The transmitter unit includes a cadmium sulfide photocell sensor responsive to access into the vehicle which will turn the transmitter off and activate a local alarm. The receiver unit constantly monitors the transmitter signal and will activate an alarm if the transmitted signal is not present for any reason, such as the vehicle being towed beyond the broadcast range.