Were does the remote blue wire connect?

So I paid Best Buy to put in an aftermarket stereo. They connected my remote wire correctly to the stereo. I ran all of the wires myself to my sub. Problem is, it won't turn on. All fuses are intact, everything is kosher (ground, wires through firewall...

I want to connect my amp to my factory head unit in my 2007 chevy cobalt.. and I took my head unit out, now all I have to figure out is which wire to connect the remote wire to.. people say blue and I've also heard red.. but there are 2 blue wires.....

i installed the starter and the bypass module and everything works great its just that i dont know what to wire to hook up to my keysense wire in my car to keep the check engine light from coming on. i am thinking its the factory alarm disarm wire from...

I have tested my power and ground wire both connected to a power meter and it reads 12v. I have tested the remote wire connected to the amp, reads 12v as well. Connected the ground wire, and connect the power, when I check power on the line after it...

I cant get into the HU since its a factory Navigation unit and there is no way I can get to the remote wire from the HU. I try to connect but no power to the amp. I also put a switch on the power wire that goes to the amp to turn on and off the power...

When I take my head unit out, I know im suppose to connect my remote to the blue wire because it turns on and off my amp...but how do I do that? Im afraid to pull out the blue wire from my head unit because im afraid it wont go back in....how do I do...