Hy BlueChipper, my suggestion would be to replace the L.E.D. bulbs with incandescent bulbs and see if the problem goes away. I had a similar problem on a panel I was helping build, everything was working fine, then the owner showed up with some L.E.D. bulbs for the rear of the truck. Once the L.E.D.s were installed both sides would flash when either side turn signal was used, hope that helps.