woh woh woh... don't cut any factory harnesses. I'll try to make it as simple as I can.
Ok, Do you have an amplifier bypass harness? Metra #70-5513
If not I have them in stock
Sounds more like you bought a 70-1770
DIRECTIONS
1) Unplug wire harnesses from both sides of amplfier.
2) Insert bypass harness between the two harnesses.
See... pretty simple ehh?? otherwise you have to unplug the harness coming out of the right side of the amplifer (output) and hardwire your speaker wires coming from your headunit into the factory wires using the factory wire codes..
