I dont know whats going on, i have no sound.

I think this truck has a factory amp that i need to somehow bypass

wow so much usefull information, i dont even know where to begin!

if you cant do a better job of describing your problem, nobody is going to be able to help you. (which is probable why it has been months with no replies)

so for starters, did you connect the amp turn on wire to the correct factory amp turn on wire?

are you using the correct wire harness?

since this is a 6+ year old model, are you sure that it works?

if you ever have any problems, you need to start with the exact year, make, and model of the car, any optional OEM equipment (onstar, bose, monsoon...) what is the exact model radio you put in, and what are the exact parts that you used. then describe what you did so far for the install, and a good description of your problem that way people will at least be able to understand what the issue could be, since we cant test the car over the internet, we need something to go off of.