Well I got the factory amp in the mail, plugged it in and there's no change. I only have the one big plug coming up out of the floor with no sign of the second one, I'm assuming that's for the factory sub that mine doesn't have. The next step is probably tracing every speaker wire but that job prett...

Yes there is a harness used, it has a second blue connector hanging off it doing nothing. Both headunits were used with the same harness witht the same wires so it's strange. The remote wire is hooked up too, though not having an amp there it probably isn't doing much at the moment.

Hello, I picked up an '03 Vibe GT last week and it's already been.. interesting. Sorry for making this my first post here I haven't seen this answered through my searching. So the car came with a JVC head unit installed, not the greatest thing but it works mostly.. I get full sound through the front...