1988 Toyota Celica Brake/Running Lights

So I checked all my fuses, relays, and the physical button under the break pedal. I replaced my bulbs. My head lights work, my turn signals work, and my reverse lights work. The running and brake lights DO NOT work. The only other thing I can think of is the rear drivers side panel is supposed to have what is called a "light failure unit" (I read it in a forum) but before I take it apart I wanted some more information/suggestions. Please help.