lost my tailights

I recently completed the restoration of a 68 Chevelle Post 300 deluxe. Got it back from painter and discovered paint overspray in connections, but fixed all those issues. Have had all lights working ever since (over a month). Got in car Friday and no tailights. When I go to check it out, the fuses are good, although there is no voltage at tailight connection. In checking other rear end lights, have both blinkers, hazards and brake lights with the exception of when the right blinker is on, no brake lights. Before I go ripping out the wiring harness is there anything else I need to check. My Body by Fisher book does not get down to the headlight switch and I do not know if there are multiple contacts when you turn on the lights are what. I know the wire is common and have it identified.
All front lights and front side markers work with no problems.

Any help would be greatly appreciated.

well now im guessing thats a commen problem with the 68's cuz my 68 does the same thing as far as the right blinker. all you have to do is when you put the right bliker on, slightly push back down on the blinker lever,(as to turn th blinker off, but not that hard), and you should feel it click slightly and move very very slightly back down, now you should have a left brake light and your right turn signal, atleast thats how mine is.

Just wanted to say thanks for the reply....Yep, you're right it does work just as you said. I've since found a diagram and the problem is in the switch. Your fix'll get me by for a while until I change it out. Thanks again!