is there a main aircon fuse besides one under steering wheel?

No. I assume you are getting no power to the pump? The ECU has locked it out and needs to be reset using a Renault CLIP system.
 
you need to see if theres power down to the compressor multi-plug

its a pig to get to....i should know did the check on mine ages ago!!!

the external temperature sensor also influences the operation of the air-con as if its too cold outside it will stop the system from working to stop icing

also pressure sensor on the end of the condensor - low gas = no working