The present invention relates to a sealing device (1) for the front-end air intake of a motor vehicle, including: a supporting frame (5) comprising two longitudinal crossmembers (5a), parallel to one another, and two side posts (5b), perpendicular to said longitudinal crossmembers (5a) and connecting said longitudinal crossmembers (5a); at least one flap (3), pivotably mounted about an axis (A) for pivoting between a sealing position and an open position, said at least one flap (3) being installed within the supporting frame (5); at least one electric control element (13) that controls the positioning of the flap(s) (3) and is capable of being connected to the electric system of the motor vehicle by at least one electricity supply cable (20), the supporting frame (5) comprising at least one device (15) for snap-fit attachment of the electricity supply cable(s) (20), said snap-fit device (15) being integral with said supporting frame (5).