If you have lost both wind speed and wind direction then the most likely cause is loss of power to the mast head unit. You need to make five connections to get the unit to work. Four coloured wires and the screen drain wire need to be connected.
The screen drain wire is the supply negative.
The red wire is +5volts.
The white wire provides a pulse for every revolution of the wind cups.
Black and blue cary analogue wind direction data. Both lines change between about 0.5 volts to 4.5 volts depending on the wind direction.
With a multimeter you should be able to work out the problem.
In my case it was just the screen not connected. Mine now works perfectly.