Motorbike LED strip brake light wiring issue

Thread Starter

Sierra11

Joined Feb 27, 2020
4
Hi guys,

I have a conundrum that i can't seem to get my head around. I have installed a pair of led strips on the rear of my bike, they remain on as red colour as long as the bike is powered on and they also switch to yellow flashing light when indicators are active. This runs additional to the bikes regular brake lights/indicators.

Now what i am trying to do is to have the full time on red lights of the strips, to flash/strobe when the bikes brakes are active (using a basic inline flasher module). However at this stage there are only two options. 1. They stay on red full time. 2. They remain off but flash when brakes are applied and turn off when brakes are off. As mentioned i would like the lights to remain on full time and also flash when brakes applied and return to full on when brakes are off.

The issue is that the bike brake light power source has three wires output. Constant voltage, Brake signal and ground. The LED strips have 3 wire input , Indicator signal wire, ground and power. If i provide the constant voltage from the bike brake plug to the brake flasher module and then to the led strips, i will just get full time on led strips (as no brake signal will be fed to the module). If i provide brake signal output to the module then i will not get full time on lights, but will get the flash effect and then off when brakes are not active. The brake module has a simple power in ground in, power out ground out set up.

Can you guys advise me as to how i can get the strip lights to remain on and flash when brake applied?

Summary of wiring for each unit

BRAKE Flasher module - Positive and Negative in ----- Positive and Negative out

BIKE Brake light plug - Ground, Constant Power, Brake active Signal power

LED Strips (pair) - Positive, Ground and Indicator Signal

Many thanks in advance!
 

djsfantasi

Joined Apr 11, 2010
6,407
When you apply the brakes, how do you do so? If it’s a mechanical switch or lever, perhaps you can piggyback an SPDT switch. The NC contacts will supply the “constant voltage” to the brake module. Once you activate the brakes, the SPDT switch will route the brake signal to the brake module.

The Common terminal of the switch is wired to the brake module. The NC connection is wired to “constant voltage”. The NO contact is then wired to the brake signal.
 

MisterBill2

Joined Jan 23, 2018
6,007
The description of the added light strips does not match the description of how they work. If they have both red and yellow LEDs then it should be one wire for ground, one wire for red, and one wire for yellow. In addition, you need to add a 12 volt relay to disconnect the red lights constant feed when the brakes are applied.
WE know nothing about the flasher module other than it has four leads. Does it interrupt the positive side or the negative side? Do the negative leads need to be connected to negative for it to flash? Let us know that and I can provide your answer.
 

Thread Starter

Sierra11

Joined Feb 27, 2020
4
When you apply the brakes, how do you do so? If it’s a mechanical switch or lever, perhaps you can piggyback an SPDT switch. The NC contacts will supply the “constant voltage” to the brake module. Once you activate the brakes, the SPDT switch will route the brake signal to the brake module.

The Common terminal of the switch is wired to the brake module. The NC connection is wired to “constant voltage”. The NO contact is then wired to the brake signal.
The brakes are applied via a hand lever on the handle bar or by the rear brake lever on the foot side. The mechanical movement physically activates a brake switch which it then provides a signal to the brake lights through the single brake plug power source.

Would this work with with a SPDT? I apologise I am not well versed with automotive electrical circuits, I am in Aviation Engineering so it is a little bit different!

The description of the added light strips does not match the description of how they work. If they have both red and yellow LEDs then it should be one wire for ground, one wire for red, and one wire for yellow. In addition, you need to add a 12 volt relay to disconnect the red lights constant feed when the brakes are applied.
WE know nothing about the flasher module other than it has four leads. Does it interrupt the positive side or the negative side? Do the negative leads need to be connected to negative for it to flash? Let us know that and I can provide your answer.
Yes that is correct, I should have clarified better. The strips have a red, yellow (indicator signal wire) and ground wire.
I unfortunately was not provided with the schematics for the flasher unit. But yes both negatives need to be connected for it to flash.
I have attached photos of the flasher unit and the brake plug power source.
 

Attachments

MisterBill2

Joined Jan 23, 2018
6,007
Yes that is correct, I should have clarified better. The strips have a red, yellow (indicator signal wire) and ground wire.
I unfortunately was not provided with the schematics for the flasher unit. But yes both negatives need to be connected for it to flash.
I have attached photos of the flasher unit and the brake plug power source.
If the flasher will work with both negatives connected to the frame ground then all you need to do is have the relay operate when the brakes are applied, and have the normally CLOSED contacts across the flasher, positive input and positive output. Then the positive input connects to the power source and the positive output to the LEDs. So normally the LED power passes through the NC relay contacts, but when the relay opens, the power passes through the flasher.
 

djsfantasi

Joined Apr 11, 2010
6,407
The brakes are applied via a hand lever on the handle bar or by the rear brake lever on the foot side. The mechanical movement physically activates a brake switch which it then provides a signal to the brake lights through the single brake plug power source.

Would this work with with a SPDT? I apologise I am not well versed with automotive electrical circuits, I am in Aviation Engineering so it is a little bit different!
Yes, but MeBull2’s (dang autocorrect) reply is even better.
 

MisterBill2

Joined Jan 23, 2018
6,007
Yes, but MeBull2’s (dang autocorrect) reply is even better.
You could also use an SPDT relay but it would make the wiring a bit more complicated and a bit less reliable. And isn't the autocorrect wonderful when it decides that it is smarter than you are. Arrogant computer programs are such a pain.
 

TeeKay6

Joined Apr 20, 2019
572
Yes that is correct, I should have clarified better. The strips have a red, yellow (indicator signal wire) and ground wire.
I unfortunately was not provided with the schematics for the flasher unit. But yes both negatives need to be connected for it to flash.
I have attached photos of the flasher unit and the brake plug power source.
Depending on where you intend to use your bike with the new brake lights, be aware that in the USA there are regulations that prescribe what kind of brake lighting you can use.
 

Thread Starter

Sierra11

Joined Feb 27, 2020
4
You could also use an SPDT relay but it would make the wiring a bit more complicated and a bit less reliable. And isn't the autocorrect wonderful when it decides that it is smarter than you are. Arrogant computer programs are such a pain.
Is it possible for you to show me a rough schematic of the relay and wiring connections as per your recommendation? Would be very much appreciated.

Depending on where you intend to use your bike with the new brake lights, be aware that in the USA there are regulations that prescribe what kind of brake lighting you can use.
I am in Australia mate, and we too have the same brake laws and hence these led strips are just additional to the standard OEM brake light on the bike. I will not be removing the original light. Just adding to it to enhance visibility in traffic.
 

MisterBill2

Joined Jan 23, 2018
6,007
I can do thatlater, when





















































Is it possible for you to show me a rough schematic of the relay and wiring connections as per your recommendation? Would be very much appreciated.



I am in Australia mate, and we too have the same brake laws and hence these led strips are just additional to the standard OEM brake light on the bike. I will not be removing the original light. Just adding to it to enhance visibility in traffic.
I can post a sketch of the circuit later, when I am at a different computer. I can give the terminal numbers for a standard automotive cube relay, if that is what you will be using.
 

Thread Starter

Sierra11

Joined Feb 27, 2020
4
Y
I can do thatlater, when






















































I can post a sketch of the circuit later, when I am at a different computer. I can give the terminal numbers for a standard automotive cube relay, if that is what you will be using.
Yes please that would be great. Yes will be using a standard automotive cube relay mate.
 
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