Amp fuses blowing and amp overheat

i've had this rockford fosgate amp p5002 hooked up about two weeks and it would work for about 5 minutes then cut off and go into thermal mode. then the other day i turned on my car and there was no beat. found out the fuses on the back of the amp blew. now i tried hooking up a bigger ground wire, which i thought would help, and both fuses on the back of the amp blew again within like 2 minutes. what's happening here?