[still1graphics]

Has anyone experienced this problem, I put a new fuel tank in the truck with a new sending unit and it seems like the fuel gage wants to work until I turn the blinkers on or the lights and it will pull the needle down past empty or with the blinker on it will cause the gauge to jump back and forth? It seems like it's a wiring issue or a ground issue. Any help or advice troubleshooting this would be much appreciated!