the switch case can't get hot on an original style switch because of the thermal overload contacts on the outside of the switch, I see your switch doesn't have those - the semi-separate part at the back of yours must be the headlight contacts, no telling if it's protected in any way - I still recommend getting a correct switch, but yes, the object of the relays is to remove the main current load from the switch itself, the only juice thru the switch becomes the small current needed to activate the relay
Bill
