Renault Scenic A/C failure?

Hi I have a 2004 Scenic and in the last 4 months the A/C has completely stopped (no fan, no heat, no cooling) then started working again after a few days or weeks on about 3 occasions. The display on the dash still shows what option I select but none work. Seemed to start when the snow in Jan got under the bonnet but last time the weaher had been dry for days. Anyone had the same and got ideas on how to fix

Keith in Camberley
May 2010