Before you go spending a bunch of money, you first need to figure out if those wires actually have a signal on them. Get any old random speaker and use some alligator clips to temporarily attach it to the speaker wires. If you hear sound, you're good to go. If not, check the settings on the...
Oh wow, OOF. Yeah dude, you dun goofed. That Suuuuuuuucks. :(
If you've ever done electronics repair, you can crack open the factory amp and hard wire some wires coming out of there, but man. Yeah. A new amp off of eBay may be your best bet for this.
You broke one of the connectors on the harness, or you broke one of the connectors on the factory amp itself? Post a picture of exactly what's going on.
Obviously you have to keep the factory headunit. With today's technology, that's not a problem. We have tools to overcome this limitation. I used my D'Amore Engineering SMD DD-1 and found that the head unit starts putting out distortion at 53 at 1kHz, so I did all of my tuning at 52 on the...