The amount of oil means very little unless it is to little,I would check the lead to the oil switch in case it is earthing out,you may see if it is frayed and touching the engine/body,but I would go for changing the switch first anyway if a quick rekky of the wiring looks ok and save hours of testing,cost you £18/20 quid from renault garage,but they do gunge up,worked for me.
a, March 2010