An electrical connector comprising: - at least one housing defining at least one row of at least one receptacle each extending from the top to the bottom sides and each adapted to receive at least one respective electrical contact, wherein said receptacle has a bottom opening adapted to allow access in the receptacle, - a carrier adapted to receive said at least one housing, said carrier having an opening associated to said bottom opening, wherein said housing is movable with respect to the carrier between a pre-assembly position and an assembled position, wherein said housing comprises a basis and, for said at least one receptacle, a flexible lance adapted to flex with respect to the basis between a lock condition wherein it is adapted to maintain an electrical contact in the receptacle, and an unlock condition wherein it does not maintain said electrical contact in the receptacle, wherein said carrier comprises a protrusion (2;4), wherein: - when the lance is in its unlock condition, upon moving the housing with respect to the carrier from the pre-assembly position toward the assembled position, the lance cooperates with the protrusion (2;4) to prevent the housing from reaching the assembled position with respect to the carrier, - when in an intermediate position, wherein the lance cooperates with the protrusion, said first and second openings (5,11) are not facing, whereby said electrical contact is not connectable with a complementary contact of an associated connector, wherein in the assembled position, said first and second openings (5, 11) are facing, whereby said electrical contact is connectable with said complementary contact of the associated connector, - when the lance is in its lock condition, upon moving the housing with respect to the carrier from the pre-assembly position toward the assembled position, the lance does not cooperate with the protrusion (2,4) thereby not preventing the housing from reaching the assembled position with respect to the carrier. - at least one housing defining at least one row of at least one receptacle each extending from the top to the bottom sides and each adapted to receive at least one respective electrical contact, wherein said receptacle has a bottom opening adapted to allow access in the receptacle, - a carrier adapted to receive said at least one housing, said carrier having an opening associated to said bottom opening, wherein said housing is movable with respect to the carrier between a pre-assembly position and an assembled position, - when the lance is in its unlock condition, upon moving the housing with respect to the carrier from the pre-assembly position toward the assembled position, the lance cooperates with the protrusion (2;4) to prevent the housing from reaching the assembled position with respect to the carrier, - when in an intermediate position, wherein the lance cooperates with the protrusion, said first and second openings (5,11) are not facing, whereby said electrical contact is not connectable with a complementary contact of an associated connector, wherein in the assembled position, said first and second openings (5, 11) are facing, whereby said electrical contact is connectable with said complementary contact of the associated connector, - when the lance is in its lock condition, upon moving the housing with respect to the carrier from the pre-assembly position toward the assembled position, the lance does not cooperate with the protrusion (2,4) thereby not preventing the housing from reaching the assembled position with respect to the carrier.