Hi Multibiker,
Thanks for the reply and info. The tail light is tungsten. I re-wired the tail light today and now run the tail light constant. On the brake light I wired it to a signal stat and have it flashing. Run time test gave me around 45 minutes. The head and tail lights were still bright. However, the signal stat stopped functioning at this point. I'm going to run another run-time test making note of the voltage at which the signal stat fails to switch. Thanks for the voltage capacity info. It will prove to be useful.

I'll have to look around for the 20W lamps. This was my first pass as a low cost solution to keep me on the road during the dark days of winter. Now the fun comes playing with making it better.