I've got an audio install problem that has me scratching my head with no ideas for cause/solution. I should mention I'm not really any kind of expert so that doesn't actually say much. Anyway... Here is my situation. I am installing a subwoofer in my 2010 TC using the stock stereo (basic model with bluetooth for phone calls, CD player, and an AUX input), amp under one seat and sub under the other. I tapped into the speaker wires at the back of the stereo using a line out converter since my amp only has low level inputs. After wiring everything else up and then testing it out I realized there was a problem: With the speaker balance set to the center the amp got very little signal but if I faded it left or right the signal would increase and the more I fade it to one side the stronger the signal gets. I fiddled with all the knobs making sure I there isn't a setting I missed or messed up and double checked all wiring. Eventually I concluded that I wired the LOC incorrectly and one of the inputs was out of phase so pulled out the head unit again and switched one of the positive and negative wire pairs to the LOC. That didn't work and now I have no idea what to do from here. Any one else have any problems like this? Does the head unit put out signals that happen to be just perfectly out of phase?