Well I had it all typed up and the server crashed.
I hope you didnt hack the cars harness off. Thats one of the worst mistakes anyone can make.
http://www.the12volt.com/installbay/...s.asp~TID~9719
All factory amps are junk. If you have one running the factory speakers they will do what they were designed to do. If you want to or have replaced the speakers, these amps need to be unhooked. They suck monkey balls in every way shape and form. So to answer you other question, YES buy a new amp.