Second row speakers amp blows fuse
 

Hey ya'll, first thanks for your time in reading this.
My 95 Suburban blows the cigarrete lighter fuse when I play the radio at high volume, I understand there is an amp that runs the speakers on the second row that is connected to that fuse. When the fuse blows, my power locks stop working, they only work with the remote. My guess is my amp overheats and pops the fuse? If so, can I replace it with an aftermarket amp without causing damage to the other components hooked to that fuse? Radio and speakers are all original except for the front door speakers.
Any feedback will be greatly appreciated.

Thanks