Car audio help

[Michael Jez]

Recently I bought a killer used amp that worked just fine in my friends car.
Its the legendary MRV1507 Alpine amp, friggn thing is known to blow windows
out of cars n such. I installed it in my car and the protection light is
blinking, very little sound comes out of the subwoofer. I was told I flooded
out the RCA grounds, can anyone tell me wtf that means ? and how do I make
this amp play ? I am setting up a audiophile sound system in my Maxima and
wanna use that amp just for 2 of my 12" Alpine Type X subs. If its broke,
where do I take it to fix it or send it out ?
Mike Jez