Ok, here's an odd one I can't figure out. When the lights are turned off (via dash switch) brake lights work correctly. Both come on when pedal is pressed. When I turn the lights on, both rear lamps work properly. Then, when brake pedal is pressed both left lights go out and only the right one shines. 1) both are new 1157 bulbs, sockets are clean and greased with dielectric. 2) wires (at least out side of the insulation) are clean and not touching anywhere. This seems to indicate the 2 wires for rear lights are grounding against each other somehow, right? I am wiring illiterate. I have the factory wiring diagram, but I can't seem to locate where this short is happening. Any ideas?