Thread: I think I have a bad short

So basically I tucked one of the relay boxes up by the battery, the larger one, into the fender well area. The way I had it was upside down, so the cover filled up with water, and then froze solid, with the relays inside the now frozen solid block of ice. This is my summation of the problem, but I have no idea where to start. Basically when I turn the key there's nothing, no power to anything. Like there's no battery, but it's at 12.6-13.3v. Sometimes, when its the first time cranking, it'll have power and the ign works through the on position, but then everything goes dead when I go to crank it, and it won't work on acc and on anymore that day.
I'm not very electrically inclined, so if it is a short, I have no idea where to begin. I've checked all fuses, cleaned and dried out the relays and relay sockets, to no avail
Any help would be appreciated. I have pics on my iPhone, but I can't figure out how to post them on it, my PC is down, any help with that?
Thanks, steve