what causes fuses to blow?

[28Marcos]

I have an infinity basslink that keeps blowing fuses, its either the fuse on the side of the sub itself, or the fuse that is part of the wire that runs to the positive terminal of the battery. when its not blowing fuses it works when it wants to.. any ideas? thanks

[4thGenTA]

you have a shortage somewhere, check your wiring and make sure there is no wire grounding