Tail Light/Brake Light wiring

I am trying to wire up multiple (4 per side) 12v bullet style lights as tail light/break lights. Originally the car used a dual filament setup so I have a 12v source coming in for the running tail lights and a second 12v source for the second filament brake lights.

I have googled this and have not found any solid information on how this is done.

My current idea is to step both 12v sources to 6v using a 6v regulator and run the tail lights off the 6v and have the brakes lights run off a combined 12v. Is this a okay way to do it?

Thanks,
Ryland

 

Are each of the lights single filament, and you want some to be tail lights, and others to be brake lights? or are they all dual filament?

I don't understand why you'd want to run 6v? anyways, if you want to connect two lights to a 12v source, and they have the same bulbs in them, and get 6v to each, just connect them in series.

 

are you going to run signal lights???

 

You still need dual filaments on each of the lights that will be "dual function".

My OT 70 wagon uses 3 single filament bullet clearance lights per side. One light is tail, one is brake, one is signal.....I did this because the original wiring was seperate brake and signals like most foreign cars had in 70

 

Sorry I was a little vague.

I want to run 4) single filament bulbs so that they are dim to be tail lights and then brighten up to be brake lights.

The reason for the 6v regulators is so the tail lights can run off the 6v and be dim and when the brakes are applied the second 6v is applied bumping the lights up to running off 12v and be fully bright.

Here is a diagram of what I am thinking:



One problem is the regulator only puts out 1.5 amps which I don't think will be sufficient unless I run one regulator per light.

Is that any clearer?

Thanks,
Ryland

 

Prove that it can work


What I think, is that your 6v will be so dim with a 12v bulb.


...and even if it was bright enough to see, I think you will get feedback between the two circuits on one filament.

Diodes can be used to prevent feedback, but why engineer a nightmarish system? Just to use single filament bulbs? I don't get it. I am guessing your red lights don't have the room for a dual filament bulb?


oh, by the way, there are sometimes on ebay, surplus special purpose ICR's that have a higher milliamp rating. I had some at 3.6 amp rating.

Back to the nightmare. I would think there might be a way to use those "trailer light converters" that are used to hook a dual filament trailer light, to a car that has the modern wiring that is like my old 70 car. It converts a 3 wire (per side) system to a two wire. Must be a way to use it....I'm too tired to think


How's the new piston rings working out on the motor???

 

You can't use the same filament for tail and brake lights. As asked are you planning on running turn signals? Still don't see the reasoning behind the 6volt regulators.Why not just do it all with dual-filaments bulbs and not have the wiring headache.You got any pictures of this 4-bulb setup?

 

Custom tail lights on the cheap are not turning out cheap...

The reason I am hesitant to use dual filament bulbs is I am trying to use single filament sealed marker lights.

I can run the 4 lights off 4 AA batteries (6v) and they seem plenty bright.

How do I measure amperage? When I put my multimeter on the amp setting and touch the leads of my battery pack I get 9 amps and when I put it inline with the lights and the battery pack I get .7 amps.

From those readings does that mean that the 1.5 amp output will be less than my AA battery pack?

Ryland

 

you can use this calculator site; just enter Volts and one more, like wattage of the bulb, or by using a meter, enter the resistance.


http://www.ohmslawcalculator.com/ohms_law_calculator.php

 

This will not work. You will still have 6v with the brake lights on. They are in parallel not series, the 6v will not add to 12v. You could change the socket.

 

Okay. So pretty much from all the sources I am seeking help all of them are saying go to a dual filament setup.

So it is looking like these are my two options:

1) Buy dual filament bulbs and sockets and modify my marker lights to work with them.

-or-

2) Have the tail lights just be tail lights and use something else for brake lights.

Ryland

 

Don't know about Oregon but marker lights aren't legal for brake lights, not eough output. Running dim lights today with all the dimbulbs driving, texting and drinking their lattes just doesn't add up.

With 4 lamps each side seems you could run 1 with a single filament, and the other three with duals, 4 would be running lights 2 for brakes, and one for signal.

Are you trying to use something with a push in bulb rather than a bayonet mount???

can you post a pic of the units you are trying to use??

You maybe could run 12 v lamps on 6v for running, then pump in 12 for brakes but why so complicated.

 

Marker lights are usually as bright as tail lights, not as bright as brake lights.

You can see brake lights clearly in daylight, you can't see tail lights clearly in daylight.

Get it?

 

I think you should sleep it off and re-design in the morning , dual filiment is the way to go ,

 

You might try using two diodes (one 5v zener and one 1n4001) in series with the tailight 12v source. Then wire another 1n4001 diode in series with the brake light 12v source. Then wire both sources (after the diodes) to the bulbs. What this gives you is 6v for tailight operation, 12v for brake and turn signal operation.

These diodes can be wired in at the existing wiring going to the existing sockets.

PM me for the diagram. Probably looking at $5 for all the parts.

 

As said earlier use the dual element bulbs and sockets,you are building a car not a 2-way radio. Using the dual filament bulbs make your two outside lights your turn sisnal and brake lights and still be tail lites too.Trying to feed everything off one filament is just asking for more problems.

 

I have decided to ditch marker light's bulbs and go with dual filament but keep the marker light lens. I am going to go with the same bulbs that the stock setup used so I can't see how that will be too dim. The original lenses are darker than the marker light lenses. I am also adding a very bright LED (gasp) third brake light to the top of the cab that should be very noticeable. I guess I never stated this but I have separate turn signals. Thank you all for the help!

Ryland

 

When you get done throw up a picture of your setup.