Fuse for wipers

I have been working on my A/C, I still have not sorted it out. I just started driving the car the other day because it was raining, and not a convertible day, and I find that the wipers are not working. They blow the fuse. I changed it once, then I started checking wires. I could not see anything loose, but the next time I tried it the wipers worked. I continued to work on the radio wiring, and when I tried the wiper again the fuse went again. Does anybody have a suggestion?