The present invention relates to an electrical connector system. The electrical connector system includes a first connector to be mated to a corresponding counter connector and it is further adapted to be connected to a signal circuit for activating an electrical power source upon switching. As a safety feature, the connector system further includes a connector position assurance (CPA) member assigned to the first connector, which is movable, whereby an end position is not reachable if the first connector is incorrectly mated to the counter connector. The CPA member is adapted to interact with the signal circuit if placed in said end position so that it activates of the electrical power source.