Hey i need help with a new stereo i am trying to install and i couldnt find a thread that matched my problem. Well i have everything hooked up and the right harness and everything, but for some reason my speakers still have no audio. There is a extra purple and yellow wire that doesnt go to the harness i bought but it connects to the back of the factory stereo. What should i do with this wire? and is it the reason why my audio isnt working?