Wiring Diagram For Trailer Hookup. Having the wires backward will cause problems. Find the trailer light wiring diagram below that corresponds to your existing configuration.

Simply creating the date using php date function should fix this issue for you, rushing to cover home. However from the mitchell's diagram i may be able to separate trailer's stop light functionality from blinkers just by disconnecting blue wire from #16 in flasher unit (stop light input), and use brake control pin on the trailer hookup for trailer's stop light. In the trailer wiring diagram and connector application chart below, use the first 5 pins, and ignore the rest.