Break Light Question

[RunnerDuck]

Since there are no stupid questions I thought I'd give it a shot!

I have a break light on the very back of the TD I'm building. No turn signal, no running light, just a break light. It has two wires, power and ground. (NOTE: I do have taillights on each side that have turn signal, break and running lights)

My question is, where do I connect a single break light?

It seems to me that if I connect it to either the "Right Turn/Break Light" or the "Left Turn/Break Light" wire from the truck, which ever one I connect it to would cause it to blink as well as show break.

Someone please help clarify this for me.

Thanks,

[RunnerDuck]

I forgot to mention that my taillights and break light are LED, if that makes any difference.

[H.A.]

N

[Redneck Teepee]

Not sure what your TV is but like H.A. says you will have to go to the downstream side of your stop light switch and feed from or tee off before it goes into the column or flasher assembly.

[pchast]

Couldn't find the receipt and will look further.

There is a circuit sold. It was less that 5$ for a 3 wire 'dohicky'(technical term) that took a signal from the two turn signals and provided the third brake light .

[noseoil]

Yep, third brake light needs a converter from the two rear lights, or another wire from the tow vehicle.
https://www.etrailer.com/p-118158.html

[RunnerDuck]

Thanks for all the comments. It looks like I'll need to go with a converter of some sort, probably the one from Etrailer.

By the way my TV is a 2003 F250.

[pchast]

I'm confused. I used a circuit from Amazon (Pacer Performance 20-702 Black Logic Circuit). This took input from the turn signals. If both were on the third brake light lit.

Are you trying to do the same or to change your TV wiring to the trailer?

[RunnerDuck]

I'm confused. I used a circuit from Amazon (Pacer Performance 20-702 Black Logic Circuit). This took input from the turn signals. If both were on the third brake light lit.

Are you trying to do the same or to change your TV wiring to the trailer?

Do the same thing. I have three old fashion taillights that are like a 1936 Ford. One on each side of the trailer and one in the middle of the galley hatch with the license plate mount. They have two bulbs, one for park lights and one for break/turn signal. It's the one on the galley hatch that I want only the break to come one and not blink with one or the other turn signals.

Update: I just looked at the Pacer Performance 20-702 Black Logic Circuit you suggested and what a bunch of terrible reviews on Amazon. I think I'll look further before I pull the trigger on that one. Thanks just the same.

[Camp4Life]

The link posted from noseoil is the way to go, however, don't cut any wires and keep the receipt. I've read that it still doesn't work properly with some vehicles, and when you hit the brake while your turn signal is on, it will still cause the 3rd brakelight to flash with the turn signal.

So just twist up the wires to test it first in case you need to return it. If that does happen to you, you'll have to run a wire up to your brake pedal and use its switch to run the 3rd brake light. Or, alternatively, if your TV already has a 3rd/highmount brake light, you can also wire into that. This also requires you to run a separate wire to your trailer that isn't part of your 4/5-pin wiring.

Lastly, if you happen to have a 5 or 7-pin connector on your TV for brakes, you can use the electric brake pin to trigger the 3rd brake light on the trailer as well since that only gets power when you brake.

[RunnerDuck]

Lastly, if you happen to have a 5 or 7-pin connector on your TV for brakes, you can use the electric brake pin to trigger the 3rd brake light on the trailer as well since that only gets power when you brake.

BINGO!!! Thank you "Camp4life" I do believe that's the answer. I do not have electric brakes on my TD so that should be the perfect solution.

Thank you so much for that suggestion.

Now the question is: "I also pull a big fifth-wheel with my truck and it has a break controller on it. I wonder what effect that will have on it.

I assume that the voltage is controlled by the break controller so it might only come on to full brightness when I press hard on the brakes. Hum?

[Camp4Life]

Lastly, if you happen to have a 5 or 7-pin connector on your TV for brakes, you can use the electric brake pin to trigger the 3rd brake light on the trailer as well since that only gets power when you brake.

BINGO!!! Thank you "Camp4life" I do believe that's the answer. I do not have electric brakes on my TD so that should be the perfect solution.

Thank you so much for that suggestion.

Now the question is: "I also pull a big fifth-wheel with my truck and it has a break controller on it. I wonder what effect that will have on it.

I assume that the voltage is controlled by the break controller so it might only come on to full brightness when I press hard on the brakes. Hum?

Glad to help! Yes the voltage is variable depending on the brake controller settings. Some vehicles, like my F-150, put out a constant 0.2v to check for a trailer connection. This shouldn't be enough to light up the lights, even LEDs. If you set your gain to max, it should light it up as soon as you touch your brake, but it might get brighter the harder you press the pedal.

One way to get around this would be to use a relay. So once the electric brake pin puts out enough juice to trigger the relay, the LED comes on full bright. I would suggest putting a resistor inline with the electric brake circuit just so there is some kind of load on the circuit. A relay is a very light load, and your controller may not work because it would think there's nothing connected (no load). But not a little circuit resistor, you need one designed to take the load and would look something like this:




This is something you'll have to experiment with because every TV and every brake controller is different, but hopefully this sets you on the right path.

-Al

[RunnerDuck]

Camp4life,

It certainly sounds like you know what you're talking about, unfortunately my electronic skills are lacking and not sure how to "experiment". I don't have a supply of resistors lying around and I have no idea what to get and how to hook up a relay.

It all makes sense but...

Thanks again,

[RunnerDuck]

UPDATE:

Thanks to Camp4life's remarks I'm able to use the brake line to turn on the brake lights. Because it goes through a break control it does tend to start a little dim but quickly gets bright. Actually I like the effect and it gets bright enough, quick enough, to not be a problem for the people behind be to see!

Thanks again to everyone for their assistance. I can now move forward to the next issue which I'm sure is not far away

[Camp4Life]

Yay!

Glad it worked out! LED's don't take much to light up so as long as you have the gain on your brake controller on max, it should be plenty bright. Enjoy the new safety light