In an open position, a power-supply terminal and a detection terminal are not connected to a mating power-supply terminal and a mating detection terminal, respectively. In a predetermined position, the power-supply terminal is connected to the mating power-supply terminal while the detection terminal is not connected to the mating detection terminal. In a closed position, the power-supply terminal and the detection terminal are connected to the mating power-supply terminal and the mating detection terminal, respectively. When the connector is turned toward the predetermined position from the closed position, a first regulating portion regulates a first regulated portion to prevent the connector from reaching the predetermined position. When the connector is turned toward the predetermined position after the regulation is released, a second regulating portion regulates a second regulated portion to prevent the connector from being turned toward the open position beyond the predetermined position.