Technical punto speedo sensor wiring

[davey]

On my 1997 fiat punto there is a speedometer sensor mounted on the gearbox....this has 3 wires coming out of it - a yellow, a blue and a brown. These wires connect in to a socket but unfortuntaly during maintenance the wires got pulled out . The wires on the other part of the socket are coloured differently --black, red/blue, and blue/white.

Can anyone help with which wires go to which ??

thanks