ok ok ok....ive been extremely confused as to how im going to run my 4-channel amp in my car.....i want to run my speaker wire from the back of my head unit to my amp.....i dont understand where to cut my existing wire behind my h.u....

 

if you're trying to run the output from the head unit to the amp and then to your speakers, you would cut the wires coming out of the head unit--before the harness that connects the outputs to your car-- then you can run those wires to your amp and then out to your speakers