im not very good with cars at all but i had ordered a witing harness from ebay and it said it fit my car but when i pulled out the stock deck it only plugged into 1 rectangular piece fit perfect but there was just another adapter that was just sitting there i ended up trying to put my aftermarket deck in and no power at all so i figured it had something to do with the other adapter that was just sitting there at first i thought it was the controls for the steering wheel. so i need help