Turn signal issue

I recently noticed that my left turn signal turns on my right rear signal as well. So I end up with both rear indicators on and only my front left. The right turn signal works perfectly fine. Anyone have this happen before and/or know how to fix this? Or know of good references for me to search out a solution. I've got finals in a couple weeks and then I'm driving from colorado to california for an internship in a couple weeks so I'm hoping this is a simple fix, or more, not a costly one.



Thanks

Start with the cheap and easy solutions, inspect the rear lamp wire harness including the ground connections, the fuses, the tailgate wire harness, and the bulb sockets all around. Replace the blinker clicker module under the dash. Consider that any trailer plug wiring or adapters may have issues. Consider that the turn signal switch multi-function lever may have gone bad.