All the rear brake lights are on the green and purple wires coming out of the chassis harness and back into the rear crossover harness. Behind the right rear speaker is where the harnesses come together into the cabin. They are all connected to each other in the multiple bullet connectors.
Additionally, I found that the four or five separate lamps in the window mounted third brake light were loose in their individual sockets. I had to pull/push them in and out a couple of times to clean up the sockets a bit and I also brushed off the individual socket lugs to make them shiny.
See my post from a few days ago about solving a misreading fuel gauge by cleaning some of the connectors and especially cleaning and rebonding the black ground wires of the harness.
Optionally, maybe we can get together at your place of work over the weekend and I can point out the areas to work on.
Land Rover Club of San Diego
1993 NAS D-110 #55 (GNUTRUK)
2004 Disco II (DSCO DOG)