An electric connection device including a first connection member to be powered by an electric current and a second conjugated connection member, the first connection member being provided with at least one luminous member having at least two states and powered by a portion of the supply current of said first connection member. The device includes a position sensor having two states and provided in the first connection member so as to be actuated by a portion of the second connection member, or a mobile portion of the first connection member driven by a portion of said second member when said members are in a connection position, thus switching the position sensor from state to the other, the latter being adapted to switch the luminous element or one of them from one state to the other depending on its own state.