2008 Dodge Charger wiper motor problem

It all started when the starter solonoid relay crapped out. I drove to the store, and when I came back out the car wouldnt start. When I turned the key to on position I could hear the fuel pump kick on and everything power wise seemed to be ok. So, I went to the fuse box and swapped out the starter relay with the wiper motor relay (same relay type, 5 pin), and the car started up. I drove to autozone and got another relay for the wiper motor. As soon as I plug in the relay it blew the 30a fuse instantly with the car off. It did this twice. I blew the only two 30amp fuses I had. I happened to have a 50amp fuse, and I know your not suppose to do this, but I was curious to see if it would work. I switched out the relays again, putting the original relay back in the wiper motor slot and the new relay into the starter slot with the 50amp fuse in place and everything seems to be working at the moment. Time will tell I guess. Any ideas? Could a short in that system happen all of a sudden like that? The other thing is when I first put the new relay in the car was running, and that was a mistake I know, I had a brain fart. I was thinking maybe that dumb move could have caused a short?