brake/directional wiring

What to do with all those wires.

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p18plywood
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brake/directional wiring

Post by p18plywood » Thu Nov 6th, 2008 4:34

Here is a really tough question. I tossed this one out on the oldplymouths site because they have more cars from the mid 50s. No clear answers yet. Here is my problem. I want to set up the brake lights so that the one in the center and the two tail lights all work together. Kind of like modern cars with that third brake light in the middle. I thought it would be a simple matter of modifying the 1950 diagram. I can't even understand how the brake lights work on the 50 model. The red wire from the brake switch that goes to the center light on a 49, goes nowhere on a 50. It is simply taped off. I don't get it. I am also assuming that the 50s are using a two element bulb. One element for the tail lights and the other for the directional/brakes. Does anyone know someone who has made this work?
Gerry
If I do get this to work, a schematic of wiring should be made part of the tech resources for this site so no one has to go through this again.

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Post by rustbucket » Thu Nov 6th, 2008 6:05

Wouldn't you just run a jumper from one of your brake lights to the middle light? As long as it is on the brake circuit, it should light with the original brake lights.

p18plywood
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brake lights

Post by p18plywood » Fri Nov 7th, 2008 4:42

That is what I thought originally, until I studied the 1950 circuit. The brake switch wire does not go to the brake light, but instead goes to the directional switch, where it overpowers the intermitent flasher when you step on the pedal and gives you one steady bright light. If you ran a jumper to the center light from one of the brake wires, the center light would also flash when that directional was turned on. I just had another idea! This could be a really simple soloution! Run jumper wires from the center brake light to the drectionals, but put some kind of one way current control in the jumpers. This way the center light could feed current to the directionals, but the directionals could not feed back to the center brake light. I don't know squat about electrical stuff, but my brother is a software engineer and that is his bag. He'll probably be able to point me in the right direction. I'll get back to this if I find out something.
Gerry

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Re: brake lights

Post by Specialdeluxe » Fri Nov 7th, 2008 12:13

p18plywood wrote:That is what I thought originally, until I studied the 1950 circuit. The brake switch wire does not go to the brake light, but instead goes to the directional switch, where it overpowers the intermitent flasher when you step on the pedal and gives you one steady bright light. If you ran a jumper to the center light from one of the brake wires, the center light would also flash when that directional was turned on. I just had another idea! This could be a really simple soloution! Run jumper wires from the center brake light to the drectionals, but put some kind of one way current control in the jumpers. This way the center light could feed current to the directionals, but the directionals could not feed back to the center brake light. I don't know squat about electrical stuff, but my brother is a software engineer and that is his bag. He'll probably be able to point me in the right direction. I'll get back to this if I find out something.
Gerry

What about putting a second bulb in the light housing and connecting it to the brake light circuit? I agree that if you jumped it you'd get a flashing center brake light.
.

Good going in your Plymouth! :driving:

Paul Schettner
'49plymouth.com - Webmaster

p18plywood
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brake light wiring

Post by p18plywood » Fri Nov 7th, 2008 6:03

I spoke to my brother Bob about the brake light question. He says it is possible to put a diode in the wiring so that current can only flow one way. This solves the problem of all the lights flashing together because of the jumper wires. However he doesen't like the idea of the brake light over riding the directional. Modern cars typically have three lights in a tail light unit, a brake, a directional and a marker, in an area of maybe 30 to 35 sq. inches. My tail light is probably less than 5 sq. inches. He pointed out that if you were at a stop light about turn right with your directional on and your foot on the brake, a car behind you would not know of you intention until you released the brake and began to turn. Two bulbs in the tail light housing would solve the problem if I could find the space to mount them. If I could find a period directional retrofit kit with the two seperate directioal lights, with the arrows in them, I would consider using that. I keep coming up with more soloution, all with good and bad points to them. Bottom line is that I want more brake light than I currently have. This is something that everyone should be concerned about.
Gerry

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brake lights

Post by p18plywood » Sat Nov 8th, 2008 5:05

I am going with the second bulb soloution for the brake lights. Not tricky, but it should get the job done. I found a site that has the bulb sockets for $2.49 ea. They also have a mind boggleing array of LED bulbs and flasher units, but that's a project for another day. For tail lights that don't have enough room for a second bulb, I think the jumper wires with a one way diode would be the next best answer.
Gerry

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Post by plym49 » Sat Nov 8th, 2008 3:01

Go to a motorcycle shop. The sell modules that will do what you want to do. This situation is commonly seen with custom bikes. There could be left and right dual filament marker lights, and a center brake light. You want directionals and all three lights to function as brake lights, so you add one of these modules. There are different types, the more expensive ones add features like 4 way hazards. They range in price from $30 to $80.

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Post by Root Beer Stand » Sun Nov 9th, 2008 12:12

plym49 wrote:Go to a motorcycle shop. The sell modules that will do what you want to do. This situation is commonly seen with custom bikes. There could be left and right dual filament marker lights, and a center brake light. You want directionals and all three lights to function as brake lights, so you add one of these modules. There are different types, the more expensive ones add features like 4 way hazards. They range in price from $30 to $80.
I need to do this too.

Seeing many with a web search. All I have found are 12VDC negative ground. :(

Will figure something out I hope!

RBS
"Lucille" the Grandkids, the Mrs, and me!!

p18plywood
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12v wiring

Post by p18plywood » Sun Nov 9th, 2008 3:40

You just hit on why so many people convert to 12v on their old cars. It's not that it is so much better,it is just that so much stuff is only avaiable in 12v. It makes life easier when you are tring to make upgrades.
Gerry

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Post by plym49 » Sun Nov 9th, 2008 6:50

Back in the day I wanted to add an eight-track radio and an FM radio to my 49 Dodge. Even then, the aftermarket units were all 12 volt negative ground. So, i used a 6v to 12 v converter and electrically isolated it and the 8 track unit from the frame of the car. Worked perfectly. Much easier than converting the entire car to 12v negative ground. I suspect that with some creativity the same could be done with the flasher unit. Not hard to isolate the unit electrically; usually mounting it on a piece of wood suffices. Easilt tucked away somewhere in the trunk.

Root Beer Stand
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Re: 12v wiring

Post by Root Beer Stand » Sun Nov 9th, 2008 8:06

p18plywood wrote:You just hit on why so many people convert to 12v on their old cars. It's not that it is so much better,it is just that so much stuff is only avaiable in 12v. It makes life easier when you are tring to make upgrades.
Gerry
Yea, finding that out way to fast :(

May consider a 12V change someday just for that reason.

RBS
"Lucille" the Grandkids, the Mrs, and me!!

Root Beer Stand
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Post by Root Beer Stand » Sun Nov 9th, 2008 8:10

plym49 wrote:Back in the day I wanted to add an eight-track radio and an FM radio to my 49 Dodge. Even then, the aftermarket units were all 12 volt negative ground. So, i used a 6v to 12 v converter and electrically isolated it and the 8 track unit from the frame of the car. Worked perfectly. Much easier than converting the entire car to 12v negative ground. I suspect that with some creativity the same could be done with the flasher unit. Not hard to isolate the unit electrically; usually mounting it on a piece of wood suffices. Easilt tucked away somewhere in the trunk.
I have no luck finding a modest priced 6-12V converter for a cd player, small amp and sub in the trunk.

Any links you could offer?

Thanks in advance!

RBS
"Lucille" the Grandkids, the Mrs, and me!!

plym49
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Post by plym49 » Sun Nov 9th, 2008 9:00

Root Beer Stand wrote:
plym49 wrote:Back in the day I wanted to add an eight-track radio and an FM radio to my 49 Dodge. Even then, the aftermarket units were all 12 volt negative ground. So, i used a 6v to 12 v converter and electrically isolated it and the 8 track unit from the frame of the car. Worked perfectly. Much easier than converting the entire car to 12v negative ground. I suspect that with some creativity the same could be done with the flasher unit. Not hard to isolate the unit electrically; usually mounting it on a piece of wood suffices. Easilt tucked away somewhere in the trunk.
I have no luck finding a modest priced 6-12V converter for a cd player, small amp and sub in the trunk.

Any links you could offer?

Thanks in advance!

RBS
I haven't tried to find one since way back when. They were an off-the-shelf item at the time. Try some of the electronics sites - you can probably build one for a few dollars worth of Radio Shack parts - not that this would be the easiest way to do it. eBay, maybe, too.

Also, it is likely that those motorcyle units would work just fine on 6 volts. The basic units are little more than cleverly packaged diodes. Just isolate it electrically from the chassis of the car, and you should be good to go.

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Post by Root Beer Stand » Tue Nov 11th, 2008 6:56

If in fact they are diodes designed for a negative ground system I can see the positive ground system making some strange effects on the lights till it is wired right. LOL
"Lucille" the Grandkids, the Mrs, and me!!

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Post by plym49 » Tue Nov 11th, 2008 7:22

You still wire it 'right'. You just remember that the car is positive ground. Basically, for any negative ground device going into a positive ground vehicle, you wire the 'hot' (or red) wire to the vehicle ground, and the devices case to the hot wire of the vehicle. You just must keep the device electrically isolated from the frame of the car, otherwise you have a short. Usually, you can mount the device on a piece of wood or plastis - anything that electrically isolates it from the car.

The device (and the car) will never know that you are fooling them both.

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