97 Cherokee Sport Blows Fuses

I own a 97 Jeep Cherokee Sport 4x4 4.0 XJ engine Auto with about 197000 miles on it. About 2 months ago I was driving down the interstate and it all of the sudden died, and would crank but not turn over. I started checking fuses and turns out one was blown. I swapped it with another fuse and it started back up. I went about 2 miles and it died again. Same fuse blew. I have not found anything that can accurately tell me what this fuse goes to. If you're standing in front of the vehicle looking at the fuse box under the hood, Starting from left, it's in the second column bottom row. It's a mini fuse and is 15 amps. My guess is it goes to the fuel pump relay. I ended up having the Jeep towed home. I replace the blown fuses and it fired right up. I drove it around for about a month and it did it again. Same fuse. Towed it home once again. This time the check engine light came on. I have no idea what code it was throwing. After finding out that that fuse may go to the fuel pump relay, I took the relay out to "inspect" it. I wanted to test it but had nothing telling me what to hook up to or how power it should or shouldn't have. So I put back in, started the vehicle, and backed it out. The check engine light is now off. I've done nothing else but replace the blown fuse and take the relay out and put it back in, and it made the check engine light go off. Could someone tell me what this fuse goes to and why it keeps blowing?