Recheck your grounds on your amp. It could be a loose connection or a bad ground causing your amp to shut off when it shakes loose or is takin to much power. I had a similar problem (my friend made a half-assed ground) and when i finally went back there to check wtf was goin on there was a hole in my carpet and the ground was very loose lol. Something i've learned is if you don't do it yourself, dont expect it to be done right.
