Brake Light Wiring Issue

[Lastwachter]

I have a 1978 GL1000. On it was an LED brake light with integrated blinkers. I removed it and went with separate brake lights and blinkers on the rear.
Here is my issue:
The brake light has 3 wires. (it did not come with directions) Red, Black and Yellow.
It doesn't matter if I put the Red brake wire into the bikes Brown wire and Yellow brake wire into the bikes Green/Yellow wire or vice versa, the light does not come on when the key is turned so that the headlight is on. The brake light does however come on when I press the brakes. The "running" brake light does come on if I continue to turn the key all the way to the right (the headlight turns off). At this point the brake has a running light and also becomes brighter during braking.

I have not attempted it with the bike engine running.

What am I doing wrong? I obviously want the rear brake light to illuminate when the head light is on and to increase in strength during braking.

I hope this makes sense. It is hard to describe. If need be I can do a short video tomorrow to demonstrate.

Thanks in advance.

[Lastwachter]

So....Any ideas guys?

[WingAdmin]

I have a 1978 GL1000. On it was an LED brake light with integrated blinkers. I removed it and went with separate brake lights and blinkers on the rear.
Here is my issue:
The brake light has 3 wires. (it did not come with directions) Red, Black and Yellow.
It doesn't matter if I put the Red brake wire into the bikes Brown wire and Yellow brake wire into the bikes Green/Yellow wire or vice versa, the light does not come on when the key is turned so that the headlight is on. The brake light does however come on when I press the brakes. The "running" brake light does come on if I continue to turn the key all the way to the right (the headlight turns off). At this point the brake has a running light and also becomes brighter during braking.

I have not attempted it with the bike engine running.

What am I doing wrong? I obviously want the rear brake light to illuminate when the head light is on and to increase in strength during braking.

I hope this makes sense. It is hard to describe. If need be I can do a short video tomorrow to demonstrate.

Thanks in advance.

I think the first thing to do is determine how the brake light works. You have red, black and yellow. I'm going to assume the black is ground - so with ground on black, try applying 12 volts to red and yellow in turn, and see what the light does.

[Lastwachter]

The red and yellow runs the light. I know this because when I plugged either the red or yellow into the bikes green/yellow wire (the braking indicator light) they both worked, the red being brighter. So I knew the red was the actual braking light and the yellow the running light. So I figured the bikes brown wire was to blame.

Eventually I figured out that I was looking at the wrong fuse for the brown wire and the fuse that went to the brown and WAS blown, looked good before I pulled it out. Long story short, I swapped out the fuse and everything is good to go!

Brown-red
Green/yellow-yellow
Green-black

All is right with the world.

Thanks for everyones input and help. Lesson learned.