I do believe that this is a duplicate thread. Still, how do you know the speakers are fine when every time you give the amp power it blows the fuse?
I would remove the positive battery cable, and connect the power and ground for the amp. Remove all connections to the amp, except power and ground, then attach the positive battery cable. If it blows the fuse, then there is a problem with the amp or maybe a short in the positive cable going to the amp. Maybe the positive amp cable is short and arcing, causing the fuse to blow. Or maybe, the positive amp cable is melted on the engine and arcing to ground.