Wondering if anyone know how you can make your tail light be a brake light/turn signal and running light? Is this possible or will you need another separate light? The lights I have are 1939 Chevy lights with a 1157 bulb in them. I have the turn signals blink and the brake lights come on, but when I pull the headlight switch for the parking lights the lights are constantly on and wont show when the brakes come on.
Wired wrong. A single 1157 was used for years for tail, stop and signal. Stop and signal are on the bright filiment, and tail is on the dim one. It's handled through a proper T/S switch
Start looking for a better bulb. Some of the china stuff the solder on the buttons is flat and touches the wrong pigtail in the socket. Then be sure of your grounds. Headlites and tail lites. Headlites switch is grounded at the dash. Check that out also.
What F&J said. The only thing on the dim side of the bulb is running lights. The stop and blinker are on the brighter filament.
Alright I will look for a better bulb. The way I have it wired now, the way it told me was (2 Wires) Green and Black. Green goes to singal and black connected the 2 lights together then makes a ground to the body. Which I thought the light grounds itself through the socket. But it works for brake light and turn signal. Just not running light.
What!?!? That doesn't make sense at all. The dim filaments in the left and right bulbs can be tied together to become the park lights and that wire (basicly) ties into the park light lead coming from the headlight switch. The other two wires for the bright filaments (left and right) go to the respective leads coming from the turn signal switch. (Assuming you have a switch that is designed to combine stop and turn signal use to 1157 bulbs of course.) The ground should be the bulb sockets themselves, IF the sockets you have are actually designed for two filament 1157's. Look up some basic wiring on google to get an idea of what you are doing. What column/turn signal switch etc are you using???
If the base of the bulb is not grounded properly then the brake/turn filament in the bulb will ground through the running light circuit. When running lights are turned on there no path to ground so no lights. Check that the bulb is grounded properly
You need to run someway to cause the turn signal to function at the same time the brake lite is operating. I copied this from somewhere on the web, might even have been here can't remember but it works. You can use a spdt switch mounted in dash.
I do think it is possible to do with the correct filaments wired, as stated previously. On a side note, I designed a circuit for LED applications that allows running lights and directionals to use the same bank of LEDs. I think it would work fine with conventional bulbs too. I am going to find out next week, as we are going to use these in-line circuits in my son's truck. When the running lights are off, the directionals work as normal. When the running lights are on, the directional interrupts the running light at the rate of the digital flasher. Later Craig
Your wires appear this be crossed. I think you have the turn/brake function going to the dim function of the bulb and the taillights going to the bright function of the bulb. Try swapping the wires at the light and report back.
Is there three wires coming out of each light or two. If three, one is definitely a ground. If two, it definitely needs mounted to metal to get a ground. While you are testing, alligator clip a wire from the bulb socket (ground) to a known good ground on the chassis
Quote "On a side note, I designed a circuit for LED applications that allows running lights and directionals to use the same bank of LEDs" Wacko1 Wacko1- I'd like to see that LED circuit.....
They are a two wire light. Green and black wire coming out. I tried switching some of the wires along. But then I would get only one to light up on running lights. But when I pressed the brake th.ey would both light up. With the headlight switch completely off
You need to check the grounds on both sockets/lamps, and then make sure you've got brake/turn to the brighter filament, and running lights to the dimmer filament. Even if you have to put a battery in the trunk and test each socket to be sure what's what. Can't keep chasing your tail and not getting anywhere with unknown grounds. The fact that you didn't get both lamps to illuminate with running lights on tells me you need to fix the grounds first.
^ yes, try hooking up a wire from the socket holder of the light to a known good ground and see what you get. Did yiu have the light screwed in or just resting, unmounted when you just tested them? With a two wire system lught, the light has to be mounted and grounded to function.
This is WRONG guys. If he actually has 1157 bulbs and sockets, this is wrong! He doesn't need to have special circuits etc...he just needs to wire what he has correctly first! Until he has THAT done correctly we can't even really guess what any other issues might be. I'm ASSUMING you have the proper stuff because thats all we can do...unless you start telling us WHAT YOU HAVE and give us a few pics even! You aren't making this easy for us 1966g10. Give us some info!!!
Simply circuit: one side of LED (cathode end) goes to ground. Other side of LED goes to current limit resistor (if LED is not already limited). Other side of resistor (or current limited LED) goes to brake/ts wire(s). Next another resistor is wired to previous resistor (side going to brake/ts wires). Lastly this second resistor goes to tail light wire. Of course you will need to do the same thing on the other side. And on a final note, the second (or tail light) resistor value will depend on what the bank of LEDs pull in current. Using 100 milliamp for an example, the calculation will be: 12V x .33 = 3.96V. So 12V-3.96V = 8.04V. Next 8.04V / .1 amps = 80.4 ohms. Use an 82 ohm, 1 watt resistor. The .33 in the above calculations is the typical PWM duty cycle for tail light LEDS, which gives you 3.96 average DC voltage. want a diagram, let me know what LEDS you are using first. Then PM me.
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