Ok, second electrical problem for the weekend (you'd think if I could wire up all the stereo equipment I have that I'd be able to figure out little crap like this... /sigh). The left brake light is working intermittently. From some past experience, I believe I've had this problem for years, but today I was finally able to reproduce it a little more consistently. With all the other lights and signals off, the left brake light is not coming on. I know it will at least sometimes come on, but other times it won't. If I turn on my headlights and/or running lights, it works fine. If the right turn signal is on, it works fine. It's only not working when no other lights or signals are turned on. All my other lights, including the left turn signal, seem to be working properly.

Note that I have TA and not a Camaro, so the brake and turn signal lights are one in the same.

I just thought of something... could it be that I have a really weak connection somewhere with just the brake light (not the turn signal) that is strong enough to control the circuit, but not strong enough to light the bulb up? So when another light is on, the brake light is being controlled by the proper circuit, but it's actually drawing power from the other circuit that is turned on? The odd combination there is the brake working when the right turn signal is on. Where would the left turn signal and left brake light lines still be seperated (by the time they get back to the back of the car, it's the same wire)? Or am I barking up the wrong tree?

Once the wires arrive past the rear seats, where the third brake light branches off, you have one + signal for both brake lights. The turn signal wire is separate. When the + brake wire gets to the back of the trunk area it again splits into left and right brake signal.
Check the wireing under the lights outside the car, also (I am sure you done this) change the bulbs, sometimes that can screw with the system.