Third Brake Light Wiring

[Uncivileng]

Hi All,
I have wired up my third brake light by tying in to my trailer brake circuit. This way it only comes on when braking, no need for a 2 to 3 converter box and additional wiring. Unfortunately the brake controller seems to put out a brief pulse every few seconds which causes the LED third brake light to flash. Doesn't bother me from the driver's seat, but could be annoying for anyone following me. Anyone else encountered this issue when wiring a third brake light this way? Is there some sort of resistor or something I could put inline to stop the brief flash? Or will I need to purchase the converter anyways?

[troubleScottie]

That is typical for just using the brake wire.

I have not tried it but using the two stop/left/right wires should give you a constant when braking, However, it will flash when turning.

The solution is the 2 to 3 converter : separates the right, left and stop signals. As a bonus, your indicator should display turning information if it is capable. ( a true brake, left, right, running display vs just a bar light )

[Squigie]

A resistor will cause a voltage drop, which may dim the LED at all times. But a capacitor on the positive side could stop the flash.
Size 'big' enough to absorb the flash, but not so big that a notable delay is caused when actually braking.

[saltydawg]

I used a light that has separate brake and turn leds so I had to use the converter. But in my mind having the brake light flash every so often might actually help some one see it. There are flash brake things for motorcycles to make the braking more obvious.

[H.A.]

A capaciator on its own might work, dont be surprised if it makes the problem worse. To put a capacitor on the circuit, the ‘pulse’ charges the capacitor, but that current still needs to go somewhere.
Dont be surprised if the lamp remains lit a longer duration than without the capacitor.
Without a designed retard circuit, You probably spend some trial & error to fix the problem.

Were I to try a ‘simple fix’. Would try using the brakes circuit to energize a relay coil. (The relay contacts obviously switching on the LED from a diffrent powersource)
Many brake controllers output a brief low current ‘pulse’ every few seconds to supervise if the brakecoils are connected. Its not high enough current actually apply the brakes, but its enough to flash a LED tailamp.
If a relay with adequate properties is used, the supervisory pulse wont actuate the relay, but brakes applied current will be high enough to actuate it.

As aside,
Its a giggle how people spend alot of effort with questionable quality converter modules and such when a standardized off the shelf solution exists using SAEJ560 lights wiring scheme and a compatibly wired vehicle.

[TimC]

After installing something similar to yours on my son's td I decided to install a third brake light on mine.

$15. Brakes, tail lights and turn signals all in one. Works great. No converter necessary. Don't be afraid to buy from R&P Carriages. A good central Illinois mom and pop trailer business.

https://www.ebay.com/itm/371070870462

[twisted lines]

https://www.ebay.com/itm/291693594366?hash=item43ea4b06fe:g:QvEAAOSwFNZWzyKE

I Opened you link and noticed the few wires, 2. "I found the one I clipped on that link"
Don't see the one in the picture doing this; Mine should untested.
Three light's "ID bar" is required over 80" wide.

[TimC]

I Opened you link and noticed the few wires, 2. "I found the one I clipped on that link"
Don't see the one in the picture doing this; Mine should untested.
Three light's "ID bar" is required over 80" wide.

Sorry, wrong link. I've updated the link to the correct light...

[Minics04]

Does your light blink when you have the right or left blinker on?

I have wired mine to the brake light but without the controller mine blinks with the right blinker on. I have not hear good results with using the controller either.

I just let mine blink. FYI.

[working on it]

...I decided to install a third brake light on mine.

$15. Brakes, tail lights and turn signals all in one. Works great. No converter necessary. Don't be afraid to buy from R&P Carriages. A good central Illinois mom and pop trailer business.

https://www.ebay.com/itm/371070870462

* I also installed a third brake light on mine, since my incandescent lights were sorta dim, and not visible enough for my liking. I chose a "Line of Fire" light strip, with brakes, tail lights and sequential turn signals all in one, placed as high up on the hatch as I could (I think the height limit for non-commercial trailers is 60" high), so I'd be sure it was visible to all.

* It came with a little circuit box attached, that handles the weird things that LED's do in non-LED wiring systems. No problems. But, they now cost upwards of $80, so if I was to install one now, the one on R&P Carriages would be my choice.

line of fire LED rear lights.jpg (52.49 KiB) Viewed 692 times

[TimC]

Does your light blink when you have the right or left blinker on? ...

I just let mine blink. FYI.

My son's blinks with the left and burns steady when braking. Good enough for his purpose. Not sure that would be legal on a wide trailer.

[DrewsBrews]

Does it not work to wire in diodes from each brake/signal light to the center brake light?