There are two things I need you to check. First, confirm fuse 33 in the fuse panel in the vehicle is good. See pics 2, 3, and 4. That fuse only powers the left rear power window.
If the fuse looks good, confirm there is power in and out from it. Here is a link you may find helpful:
If that appears good, then I need you to check the ground for that motor. See pic 1. It is a black wire which is attached at the "C" pillar. Check the black wire between the rear door switch and ground for continuity. Have the connector at the switch disconnected when doing this.
Let me know what you find.
Images (Click to enlarge)
Thursday, November 19th, 2020 AT 7:15 PM