Patent ID: 7022943

Claim:
An engine block heating system for an engine having an electric starting circuit, comprising: at least one electrical heating element; a connector port coupled to said at least one electrical heating element, wherein said at least one electrical heating element receives electricity through said connector port; a power cord that is selectively connectable to said connector port for coupling said connector port to an external source of electricity; a sensor at said connector port for detecting when said power cord is physically connected to said connector port; a first terminal connection connectable to the electric starting circuit; a second terminal connection connectable to the electric starting circuit; and a first switch coupled to said sensor, said first terminal connection and said second terminal connection for selectively connecting and disconnecting said first terminal connection and said second terminal connection, wherein said first switch disconnects said first terminal connection and said second terminal connection when said sensor detects that said power cord is coupled to said connector, and interconnects said first terminal connection and said second terminal connection when said power cord is removed from said connector.