I've seen lots of post about the headlight harness upgrade. But unfortunately no one says where they have gotten there's at. I have also seen that there are sites that say I need to use the negative switch harness to get this to work correctly, but all the harnesses I have found say nothing about the negative switch harnesses. I've tested the stock plug and I do see when I turn on the head light the negative actually activates the low beam and also the high beam in the connectors. So the negative switch harness makes sense. I almost want to try to make my own, but I know not having the connectors it will not look as nice as if I bought the harness Pre-made.