The invention concerns an assembly (1) for producing a motor vehicle windscreen wiping system (3), including an end fitting (5) of a wiper arm (7) adapted to move a wiper (9), a hydraulic and/or electrical connector (11) for feeding a liquid to the wiper and/or for heating the liquid, said end fitting (5) being configured to accept an adapter (13) allowing rotation between said arm (7) and the wiper (9), said end fitting (5) internally accepting said connector (11), said end fitting (5) being configured to engage said hydraulic and/or electrical connector (11), in an oriented manner relative to the end fitting (5), in a so-called service position, allowing the disconnection and/or the connection of the connector (11) on the arm (7).