Patent ID: 8031061

Claim:
An alarm device for use with a vehicle, the device comprising: a first connector for electrical connection with a vehicle trailer wiring receptacle of a vehicle; a second connector for electrical connection with a trailer wiring connector of a trailer; a power line electrically connecting the first connector to the second connector to deliver vehicle power from the first connector to the second connector; a signal path electrically connecting the first connector to the second connector to deliver electrical signals from the vehicle to the electrically operable components on the trailer when the vehicle trailer wiring receptacle is connected with the first connector and the trailer wiring receptacle is connected with the second connector; an alarm component electrically connected in series between the first and second connectors, the alarm component being configured to detect an electrical condition indicating an unauthorized attempt to separate the trailer from the vehicle and produce a corresponding alert signal; and a sensor mountable to one of the trailer and an item carried by the trailer, wherein the alarm component and the sensor are disposed within a communication circuit covering a predetermined area, wherein the sensor is configured to provide an alert signal when the communication circuit is broken by removal of the sensor from the communication circuit.