Just to let you know. If the Heater Blower does not work on 1/2/3 and only on 4 then the Heater Blower Resisitor is broken. Its made by Valeo and after trying Euro Car Parts and other main suppliers you cannot buy this part apart from Renault themselves. It costs £66 and is screwed into the heater blower fan under the o/s scuttle panel. easy to replace and a simple fix. Took me half and hour and only the need for a 6mm socket and spanner.
Good luck
Good luck