No Brake Lights

Hi, Wish to ask the group an electrical question. 66 GTO conv., no brake lights, tail and signal working, brake switch ok. Traced wire after brake switch to curved connector near steering column where it goes from white (after brake switch) to black with white tracer after curved connection, then up steering column to turn signal switch. Now, here's where I am guessing a bit. Wires from curved connector do not continue on past turn switch other than back down the same connector, Please confirm. I should read continuity at pin location sourced from closed brake switch up the column to one of the other pins in that same connector to show current path to rear harness. I am concluding a failed turn signal switch, can anyone confirm this? Another puzzler, I separated the rear harness connector under the rear seat trying to trace the problem and found one contact with voltage reading of about 8 volts I think it was third from the left with the ribbon laying flat. I haven't put effort into that situation as of yet. I know I have thrown a lot out here, I am tearing the car apart trying to trace this. Your insights would be greatly appreciated.
Best Regards, Paul

I had a similar problem. The brake lights leave switch to the turn signal switch since the same bulb does turn signals and brake lighting. From there it goes to the ribbon cable from the front to the rear. I traced mine from the colunm to the ribbon cable and it was good. At the ribbon cable behind the rear seat, mine is actually in the trunk,I found low voltage. It turned out to be a short in the ribbon cable from the resto work. Ames sells a wiring diagram that is color coded that helps a lot. I think I have a copy at home I could scan and send you if you need but they are just a few dollars and handy to have.

Tiger Gold,
Thanks for your reply and insights. I have concluded a failed turn signal switch and have ordered a replacement. Once this is installed I will verify the low volt reading at that one location. I am thinking that it could be from the gas gauge sending unit therefore, the lower voltage however, it is an off the sleeve guess. I am hoping the new switch does the trick since there were no other issues before the brake light situation. Appreciate your offer for the diagram, will get one from Ames should it become necessary. Will post final results once switch is installed.
Best Regards, Paul

I think you are on the right track. I forgot to mention if your turn signals work it probably could not be the ribbon cable. Luck.