a trailer is provided having an electrical power connector for coupling a multi - conductor jumper cable plug between trailers connected in tandem , the connector comprising a multi - prong electrical power receptacle mounted to a trailer . one prong of the receptacle is electrically connected with the electrical power to the rear stop lights of the trailer . the connector further contains a switch for interrupting electrical power to the rear stop lights of the trailer when the jumper cable plug is connected to the receptacle while allowing electrical power to pass from the prong into the plug to supply electrical power to rear stop lights of a following trailer .