VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Another dumb signal light question

Diagram with signal directions shows separate wires to each brake light.
Car wiring harness diagram shows one wire connecting both lights.
Do we need to install new wires to replace existing?

My 41 original only had two wires to the rear lights. One for when the headlights were on and one for the brake lights. When I changed to blinkers I used dual filament bulbs. For this reason there are three wires going to my tail lights. One to the right, one to the left and one that is for when the headlights are on. I had to also modify the sockets for this . Due to the age of the wiring all of the wires were replaced.

. To save a few pennies, many auto manufacturers used the Left and right rear brake lights for the turn signals. You will need to add one wire from dash to brake light. Also a wire from the stop light switch to the signal switch. If you use separate lights for signals, you will need to add two wires to the rear. .
. In front, the parking lights are not bright enough to use for turn signals so you need to add 15 candle power (CP) or greater bulbs to additional fixtures or in some cases in the late 1940s 1154 bulbs can be added that have 3 & 21 CP to the existing sockets. .
. If you have a 1932 coupe and want to use the cowl lights, use 209 bulbs for 6 volt or 1003 bulbs for 12 volt. Separate the right and left wires. If you want to use cowl lights for parking lights as well, a circuit with two diodes and a separate switch will allow you to illuminate both cowl lights. (No details here.) .
. I assume you have a 7 wire turn signal. A 4 wire uses separate turn light fixtures front and rear. .
Lou .

There are lots of posts about adding turn signals to these classic vehicles.

On my ‘37 I had independent turn signals front and rear. I had a 4 wire switch to control them. The person who bought the car converted to a 7 wire switch that meant that he was able to use the single filament brake light bulb as the turn signal. He had to disconnect the original brake light wire at the taillights. It is connected to the 7 wire controller. He connected my original left and right turn signal wires to the controller and the brake light bulbs. In the front he left the original independent turn signals.


We added turn signals to a ‘49 3100. We used a 7 wire controller. We had 2 single filament bulbs in each original rear taillight housing. The brighter bulb is the brake/turn signal bulb. We did have to convert the front parking light housing to a dual filament socket and bulb plus run 2 extra wires to the front.

The 7 wire controller is the key to using the brake light bulb as the turn signal.

Yes. 7 wire.
Thanks for the info. Much appreciated.
Got 1154 double filament 6 v bulbs for the cowl lights to act as signal and parking lights.
Are there brighter 6 v bulbs available for brake and tail lights?
Don't really want to go the led route if possible. Guess I'm too old school.

What are the stock bulbs? If 63 use 81 instead. Twice as bright. If you have the room in the housing use 1129 for brake lights. It's a larger bulb so there may not be enough room. It can be used in the 37-38 housing, don't know about the 32. Paint the inside of your housings gloss white. After watching the video below I've been thinking about experimenting with this film in my 38's housings. I bought a few sheets to play with.

All wires connected as per instructions (far as I can tell). Front signals ok but no rear. Brake lights working. Suggestions?

Re-checked wiring - again. Can't tell left from right some days. Fixed it. Now got signal lights but no brake lights. Fuse! Shoulda known. Thanks and sorry for the bother.