Make sure the amp isn't on. I mean make sure it's not on all the time, b/c there should be no power going to the amp if your radio is off. Lastly, leave the fuse out, connect the sub, then install the fuse, that way you know there is no possible way there is power going to the amp. Subs are pretty tough, I doubt that little did anything, if anything, I would think it would mess up the amp. But try what I said above first.