LEFT REAR RUNNING LIGHTS, ALL 3, ARE INOP

Hello, I would be concerned about a possible wiring concern in that area. First, does your vehicle have an add-on wiring for a trailer? If so, focus your attention there first, as there could be a problem. Second -- check the wiring on any flex points - like at the lift gate, where it comes through. Wires can become pinched there and be problematic. Either way, hands on electrical testing is needed.