The Stovebolt Site Forums The Shop Area The Electrical Bay Wiring my led tail light /headlight from scratch

If any of you have done this in an old vehicle (in my case a 1939 chevy converted to 12 volt) from start to finsh ,,I could use some help on doing it right.

I will tell you that I have the 7 wire turn signal control on the steering colume all ready to wire up

I will run a 12 ga wire (from the battery )to a fuse 14 amp then on to the flasher's X prong and from there to the turn signal with 16 ga

I will run a 12 ga wire from battery to the brake light switch then from there to the turn signal with 16 ga wire

I will use 16 ga for tail light led's and also for the headlight that have led's at the bottom of the seal beam

I already have the headlights..brake lights wired

I have double filiment bulb hook up (1157)for the brake lights and tail lights ( the new Led's have a twist in thing just like the end of a tail light bulb do .

My plan is to use a EP-28 flasher /with a clamp on mounting bracket Under the dash or on the inner fender wall of the vehicle ,,,any thoughts on this?

I have been told that I need not run an extra wire to the tail lights to use for brake lights ,,,, when you use the brake lights by pushing the brake peddle down,, this brake switch wire to the turn signal activates a higher voltage that therfore makes the tail lights brighter,, any thoughts on this being a true statement?

I will stop here and await for any and all advice and questions

thx for reading

I have not used an aftermarket switch, sorry.

Maybe, Cletis/Charlie's Tech Tip will help, if you have nor already read it.

(we miss you, Charlie).

I have been told that I need not run an extra wire to the tail lights to use for brake lights ,,,, when you use the brake lights by pushing the brake peddle down,, this brake switch wire to the turn signal activates a higher voltage that therfore makes the tail lights brighter,, any thoughts on this being a true statement?

Let's put it this way: Follow the wiring diagram for a 7 wire turn signal switch. I can't tell, when you say "extra wire", how many wires you think you need and therefor what an "extra" wire means to you. I also don't know how many tail lights you are using. Assume one each side.

There are two filaments inside the rear light bulbs, as you said. One filament is for stop and brake and is wired from the T/S switch. The other filament is for run lights and is wired from the headlight switch. When making a turn, the T/S switch shuts off the brake switch current to the necessary bulb to allow it to flash. A "higher voltage" is not the explanation. The turn signal switch is an "electrical router".

General rear wiring:
One wire to the rear for run lights, from headlight switch. That wire is split, at the rear, to run to each light (left and right). Two separate wires from the T/S switch go back. One for left turn/brake, one for right turn/brake. Tap into or wire for, license plate light and/or third brake as needed.

The flasher "X" terminal is the voltage input as you say. The device belongs inside the cab.

I don't know much about LED requirements.

There are some main feed wires from the battery for things. These wires should have an inline fusible link where they leave the battery. Otherwise they are not protected. The main battery cable to starter does not need protection.

Thx for the input Bartamos..

Hope this enlightens you with better info on what I have stated above


I have one tail light for the left and one for the right .
I do not have running lights and do not plan on wiring them in..I do have driving lights that come on with the headlight switch.
I think you need a 8 wire turn signal for that. and as I stated I have double element bulbs which I have taken out and put in Led bulbs ,,,(which I imagine only part of the LED bulbs light up for driving lights and when you want brake lights the other bulbs light up )
I get this by what you said ,,and it makes good sense,, if I am reading you correctly..

So , I must have two wires feeing the tail lights ,one from the brake peddle stop switch thru the turnsignal switch

And another from the head light switch

I can see that when you have the headlight on you will have one element lit up and when you hit the brake another element is lit up making it a two lit element bulb

So what happens when you do not have the head lights on and you hit the brake peddle to make the tail light light up brighter ?

Running lights/ driving lights/tail lights, in my book are all the same. In other words the lights in the rear that come on with the headlight switch. Usually turned on a night.

Now speaking of those tail lights: One of the filaments in the tail light bulb is the tail light filament. You have two tail lights so you have a tail light filament in each. A wire from the headlight switch (the switch that turns on the headlights and the tail lights) goes back to the rear. That wire is split (t'ed off/spliced/connectorized, whatever) and run to each tail light's tail light/running light/driving light socket contact.

Then you also have two more wires going back separately, one to each tail light's stop/brake socket contact.

So three wires going back.

PLEASE NOTE: My comments and instruction are for a normal incandescent bulb system with a normal aftermarket turn signal switch and a normal headlight switch. As I already said I DO NOT KNOW the requirements for LED. The concept of filaments does not apply to LED. LED's "increase brightness"

If you have an 1157 LED "bulb" and it has two contacts, then I guess it's wired the same as I describe. Again my explanation about tail lights/stop lights/turn signal lights/ turn signal switch is ALL based on an incandescent system. Your "higher Voltage" comment could be true. I guess.

Park and tails are seperate circuits, not associated with your 7 wire switch


I did my 50 from scratch with help from cletis

Draw your circuits on paper. It will help you

...click...


For your LED just wire the brighter wire to the stops,

If you put your flasher on the inner fender you wont hear the “clcik,click”

Very well explained Mopar..

My headlight switch is a two clicker ,,first one parking lights and second one head lights ,but,,,there are no parking lights on my vehicle and I believe it was a option to have them,, it is for dash lights only I guess

So the system i chose will not have parking lights ,, and if I had wanted them ,,then the 8 wire turn signal switch is what I would had and it would turn on the LED amber lights that are at the bottom of my headlight seal beams,,

The head light amber turn signal lights are,,,,,in my case only for turn signal and are activated thru the turning signal switch I have installed on the steeing wheel..

I will see where the 3 wires are ,, probably find the brake wire from its switch and where it goes into a loom towards the rear ..

if you think of anything more on this ,,feel free to let me know as I am a learner at this point not a teacher..thx

Who is Mopar?

Sorry ,,, This compliment was meant for you bartamos,,, Mopar is another persson whom I ask questions to..

Dads 50 ..you have a good point ,, will look under the dash some more for a place to install the flasher.. mu hearing isnt as good as it used to be and even then ,,bet I couldnt of heeeered it.. under the hood.

I do have a drawing ,,what I was no sure of is how to incorporate it with what I already have ..I'm getting there with some fine help.. where at in Nevada ? Wells ,Parumph, Elco , Winnemucca or the big city ?

10-4

This is what I have in wiring that runs back next to the left tail light area

Two wires run back to two 30 amp fuses

From both these fuses is small black wires going to the left tail light

Two wires are then run from one of the fuses ,,, one goes to the right tail light and the other goes to the license plate light

Another wire from the other fuse goes to the license plate light and then on to the right tail light .

As referenced by Tim a few posts ago there is at least 1 or 3 Tech Tips on turn signal and light wiring in our Tech Tips menu. You might want to check there 🤷🏼‍♂️

You spelled trunk wrong three times or you have a truck car. You are doing LCD with cloth wiring. You are describing colors/stripes of wire that means nothing to us. You are talking about wires "coming back" to fuses like the fuses are somewhere in the back of the car.

You now have one brake light wire that lights both brake lights. THAT MUST BE CHANGED to two separate brake/turn wires (left and right, operated by, and thru, the turn signal switch). You have one wire for both your driving/tail lights and license light (all connected together and operated by the headlight switch). That is OK. ................ two + one = 3. Provide/change/add/modify/redo the necessary wires to the rear and wire the T/S switch per instructions and you are done.

Many of the online diagrams showing the 7 wire turn signal wiring don't really show three wires very clearly. They show one for left, one for right and the third is hard to see because it DOES NOT come from the turn signal switch. Some diagrams say "rear tail lights not shown". Some say "existing tail light wiring unchanged". Some don't show or say anything because they know you have tail light wiring and they are just showing how to wire the turn signal switch.

DADS50,

I have the same wiring schematic that you linked to. Question, do your turn signals remain 'hot' when wired this way? Mine do and I assume it's so the emergency flashers will work when the truck is not running.

Thanks,

My is not hot all the time

It is better the way you wired yours.


I chose to wire mine so it hot with the key

Tim ,, I have looked at Charlies tech tips and they are help ,,he must of been a great guy for wiring help on your trucks ,,I too wish he were here so I could of private mailed him for my questions ,that way it would of been off the forum

Bartamos. I hate excuses but this time I am going to use one ,, I usually do not make so many mistakes with spelling and my explanations as I did above ,,pain pills with my back being out seems to do that to me,, sorry for the that as you have been great help with your explanations to me. I did go back and try and clean my post up a bit ..

Dads50 ,,thanks for your input ,, I will look into this further about what you said above in your reply to me (For your LED just wire the brighter wire to the stops)

Handy Andy ,thx for your input ,,I have not wired up anything yet ,so cannot answer your question

Idaho, feel free to post ALL your car questions in the Greasy Spoon. Not everyone reads the Spoon, but a fair amount do. If I see your not getting the answers to your questions there I will PM one of the knowledgeable folks in that area and have them check your post out. Also check your PM’s.