wiring help, please....

I got the Show Chrome Accessories (Big Bike Parts) Elliptical Driving Light Kit - VTX 1300/1800 for my '06 1300 C. I installed them as instructed, and they worked just fine for a day or two, then they blew the fuse. The wire the fuse is on goes from the battery positive terminal, through the fuse, then into the relay. The coating on the wire that's on the relay side of the fuse actually melted a bit before blowing the fuse. Well, I replaced the fuse to see how fast it heats up, and it's slow, but does get too hot to touch. I didn't want to waste the fuse, so I stopped there, to seek your expert help...lol. I still have lights when this is going on, as long as I turn them off before it gets hot enough blow the fuse. As long as I have the switch off, the wiring stays cool. Is it maybe a bad relay???switch???installer(me)??? Any help would be appreciated, thanks.