When replacing all of the tail light bulbs and lenses on our '78, I was perplexed to find that the outer tail light was a dual filament--but only the filament for clearance lights was working... First thinking it was the bulbs, I checked them, but that wasn't it, so I tore into the area behind the housing and found the wire for the stop/brake filament was lying there loose. In fact, it appeared to have never been connected to the wiring harness on either side. I wonder if everybody else's are that way?
I had always been concerned about people seeing the brake lights and turn signals on our '72, since it only has one small round light for both. I wanted to add a little visual intensity to prevent someone from rear-ending us (there's a tragic photo of this on Andy's website http://www.inlandrv.com/airstream-pics01/crunch101.htm
). So, I hooked up the wire to the other brake/turn light signal.
Below are the pictures before and after my modification...pretend in your mind that the clearance lights are off and the brakes are activated. I actually have a tester gizmo that I use for that purpose.
Let me know if you think this violates any safety laws. I can't imagine what the drawback would be to having an extra indicator for stops and turns, especially since it seems to be the way it was intended from the manufacturer of the tail lights.