please fit anew sensor in the o/s door mirror ,it might be much cheaper to get one of a scrap megane, at a renault breakers due to the fact they are not that cheap when you see what you get for your money , and if you are going to fit the sensor your self be carefull not to break the mirror and the outer cover ,once they are removed you just need to remove the sensor and solder the new sensor onto the old wires.
mark
May 2008