[VAC] Re: 1950's taillight wiring

["Fred Coldwell" <Agrijeep@xxxxxxxxx>]

RJ:

   In 1955, many cars still had 6 volt electrical systems. 
By 1957, most had changed to 12 volts.  The Bargman #9 tail
lights span this era.  

   The dual element bulb with both bayonets at the same
height is the 6 volt dual element bulb, # 1154 (the bulb
also looks like it says T1126 on the side of its base). 
Sometimes you see older 6 volt cars driving at night with
one tail light brighter than the other.  The reason is the
bulbs have been put in differently, one with the dimmer
filament for the tail light (the correct way) and the other
with the brighter filament for the tail light (incorrect,
the brighter filament should be the stop and turn light). 

   The 12 volt dual filament bulb 1157 had offset bayonets
for 2 reasons, to distinguish it from the earlier 6 volt
dual filament bulb and the make it very difficult to install
incorrectly (a few people can nevertheless overcome this
obstacle) because the different height bayonets orient the
bulb in one direction only, with the brighter filament as
the stop and turn light.

   You do not mention a tail light in your Bargman #9, 
Typically, the smaller (dimmer) filament on a dual filament
bulb is the tail light and the larger (brighter) filament is
the stop and turn signal light.  Often the brake switch is
wired through the turn signal.  If the turn signal is
disengaged, the brake light switch lights up the larger
(brighter) filament as the stop light independent of the
tail light.  If the brake light is on when you engage the
turn signal, the turn signal switch and blinker periodically
turn the brake light (large filament) off, thus causing it
to blink when the brakes are applied.  

   There are other variations of turn signal and wiring
schemes to help confuse things. 

   What are you doing for tail lights on your 57 FC?  I
would think they would be the small (dimmer) filament in the
Bargman #9.   

Fred Coldwell