Ok quick question. I am installing a switch that is on and off and lights up. The switch calls for 3 wires. Accessory 12v-only when car is on, power and ground. I have power and ground and the accessory. The accessory is wired to the defroster. As soon as I flipped the switched to the on position the fuse blew. I checked all connections and everything was fine. I dont understand this at all. When I just used the switch without the light it worked fine. I feel much safer when the switch is light up. I am assuming that all 12v sources have the same power so I dont understand why this happend, anyone? Thanks!