Scenic 2003, Reversing Light Fuse Blowing then car won't start?

Renault Megane Scenic Fidji 2003. Reversing light only rarely worked. Got garage to look at it recently and in process of ordering new switch. Problem is though the fuse on this circuit is occasionally blowing (possibly something mechanic has done). Fair enough i can live without a reversing light for a bit, what i can't get my head around is that when this 15A fuse blows i cannot start the car. Can anyone enlighten me as to what other circuits Fuse19 feeds. I believe it also feeds the wipers front and rear, but what else? Need help...thanks