After you do some tests as I explained, we will be closer to answering the crosswire and ground questions. Bottom line to always remember when doubting this and that is: Something is wrong! Something needs to be tested and found. Something needs fixed! No one knows what it is yet. A troubleshooter NEVER assumes anything is correct because something isn't. I have run a wire from my battery ground back to my tail lights and touch it hard against bezel, then socket, then bulb base to get them to light because you have to sometimes bypass every ground to get a baseline. If the bulb doesn't light then, you know it ain't a ground problem. Let us know what you find out and we can continue to help or maybe you will fix it. Thanks
