A connector part extends outward of a yoke housing from a holder base and is connectable with an external connector to receive an electric signal. A contact base extends from the holder base into an interior of the gear housing through a communication hole, which is formed in a yoke housing side end of the gear housing. The contact base supports terminals, which provide an electrical connection between stationary contacts and brushes. An intermittent drive unit is installed to the connector part to intermittently drive an armature through the brushes based on the electric signal received from the external connector.