I really have no idea on that one bro, and I am not entirely sure that is your problem either. But I would deffinitly get a distribution block, and some 4 guage wiring to set it up properly and go from there.
One way to eliminate the amp as a problem would be to get a 3.5mm to RCA cable (RCA's on one end and a headphone jack on the other.) Then you can use a portable device (CD player, DVD player, Ipod, etc.) and hook it up to your amplifier via the RCA inputs. If everything works then your head unit is the problem, or RCA's are grounding out, but it elimates your amplifier as being the problem.
And if it still doesnt work, then it would mean your amplifier is the problem //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif