1997 Iveco 3510 Turbo Daily Classic - Headlight Switch?

I push my headlamp switch on and it keeps blowing both side/headlight 10amp fuses in fusebox at same time. Ive heard of water getting into the fusebox itself but everything else works fine/rest of lights etc so i just presume its a faulty switch/open circuit thats why fuses keep blowing. Anyone else had this problem.