sinness1

I just bought new amp (power acoustik ps2-1200) which is a two channel 1200 watt amp, it is 4ohms and 2ohms stable. i have it wired mono to a 1300 watt 4ohm sony subwoofer. it was working fine for about a week but then all of the sudden it cut out. the fuse was blown by the battery so i bought a new one and put it in. the subs worked for about five seconds then cut out again and the new fuse blew. so i looked at all the wiring and i noticed that my ground cable had a bad connection and the insulation on the wire was melting... so i went home and re crimped the wire and hooked it back up to the amp and when i turned my stereo back on, it worked but the sub sounded real distorted like it was blown, then after about a minute of it running, it turned off and the amp light turned red. i turned my stereo back on and the green amp light came on but it was flickering. I thought maybe it was to small of a fuse by the battery (50) so i bought a 60. i put the fuse in and turned my stereo on and the green light on the amp was solid and not flickering.. but now the sub isnt making any noise at all? any ideas? i dont know wether to return the amp or the sub..