Does anyone have a wiring diagram for the taillights (and how they illuminate when pressing on the brake pedal? I want to see if I can create my own control board for sequential taillights and I am not familiar with the wiring or operation of the car.
No wiring diagram here but it is easy to sort out with a meter. The inner light on each side has no wire for brake/turn power even though the socket is a dual filament. It is possible to wire it from my past experiments. I believe each brake/turn light receives power on separate wires from the last plug in the back.
As AZPete says, each light does in fact have a different color code on the wire that supplies power while braking. If you could scrounge a 3-wire plug for the inner light that would actually be pretty easy to splice in.