I suspect there is an issue with splice 307. At that point, the black wire with a yellow tracer is spliced together for the rear lights.
If you look below, pic 1 shows the schematic. Pic 2 is the location of the splice, so you will need to pull the carpet back in the area shown.
Locate the black/yellow wire splice and inspect it for corrosion or damage. With the lights on, have a helper stand in the rear of the vehicle while you wiggle the splice to see if the lights turn on and off.
Let me know what you find.
See pics below.
Images (Click to enlarge)
Thursday, February 16th, 2023 AT 8:55 PM