Brake Lights don't work when braking

[Jason5885]

I noticed last night that my brake lights are on solid. When I operate the back brake or the front break the brake light is always on, even when back and front break aren't being operated the light is solid.

Any ideas?

[HKr1]

Check the switches...

[csmith12]

Originally Posted by HKr1

Check the switches...

^^^ yep, I would pay close attention to the rear switch.

[Jason5885]

Originally Posted by HKr1

Check the switches...

Originally Posted by csmith12

^^^ yep, I would pay close attention to the rear switch.

Where are these switches located exactly? Could one switch cause a problem with both brakes?

EDIT just checked my service manual. Will have a play about with the switches tonight.

[csmith12]

In the above pic, the rear brake light switch is the wire above the rearset, just in front of the brake res. hose. When viewed from underneath, you will find a thin connecting rod that runs from the brake lever to the switch. Ensure that it is clean and moves freely. Then check that it operates with the foot lever. It works in opposite, meaning... when the foot lever is pushed down the pin will pull inward, making the electrical contacts for your brake light. Vice versa for when the lever is released, the pin will be pulled outward breaking the electrical connection.

The front is similar in how it works. It's a simple button, pull the hand lever to push the button. Again, ensure everything is clean and moves freely.

[Jason5885]

Originally Posted by csmith12

In the above pic, the rear brake light switch is the wire above the rearset, just in front of the brake res. hose. When viewed from underneath, you will find a thin connecting rod that runs from the brake lever to the switch. Ensure that it is clean and moves freely. Then check that it operates with the foot lever. It works in opposite, meaning... when the foot lever is pushed down the pin will pull inward, making the electrical contacts for your brake light. Vice versa for when the lever is released, the pin will be pulled outward breaking the electrical connection.

The front is similar in how it works. It's a simple button, pull the hand lever to push the button. Again, ensure everything is clean and moves freely.

This makes sense to me, thanks Chris, I'll have a look tonight and see if i can source the problem. I hope it's as simple as that.

[csmith12]

Np Jason, another issue the thin connecting rod may be missing altogether.

[Alex]

Check the bulb before you go too deep into troubleshooting elsewhere. It's a dual-filament, so the brake element could be non-functional while the tail-light/running-light filament is working fine.

The fact that neither the front brake switch nor rear brake switch appear to be triggering the light points more to a bulb issue than a sensor issue.

[Jason5885]

Originally Posted by csmith12

Np Jason, another issue the thin connecting rod may be missing altogether.

Originally Posted by Alex

Check the bulb before you go too deep into troubleshooting elsewhere. It's a dual-filament, so the brake element could be non-functional while the tail-light/running-light filament is working fine.

The fact that neither the front brake switch nor rear brake switch appear to be triggering the light points more to a bulb issue than a sensor issue.

Ok so I've sourced the issue..

The small switch that your front brake lever is meant to cover when you aren't braking, and when you do break the level allows the switch to Pop out, is not being covered by the brake lever.

I'm using the ebay adjustable levers and the bit that covers this little button/switch is just short of covering it. i don't know why it's only just happened now? Can this little button be adjusted so the lever covers it properly ?

[csmith12]

Post a pic, I aint quite following what your saying.

[Jason5885]

Originally Posted by csmith12

Post a pic, I aint quite following what your saying.

I will when i'm home from work today.

But basically, when you arent pulling your brake lever and its in its stationary position, its covering a small button, and when that button is pressed in, the brake light is not in operation. As soon as you pull your brake lever, it moves away from the button , thus not pressing it anymore, which triggers the brake light to turn on.

My problem is, wether my lever is in operation or not, the button isn't being covered. Thus my light is permanently on.

[Somchai]

Jason, didn't you say that your bike fell two times down on the right side, so could it be that the lever is bent?

[Jason5885]

Originally Posted by Somchai

Jason, didn't you say that your bike fell two times down on the right side, so could it be that the lever is bent?

It was happening before it fell. The bar is replaced now too. I think theres a small allen screw on the button assembly, pehaps i can move the button closer to the lever.

[csmith12]

There is no adjustment to move it closer that I know of. It sounds as if it is broken internally and you will need a new one.

Here is what I would do;

Pull and release the lever, hear a click? No click, switch is most likely broken internally. Replace switch.
Check the prongs on the back of the switch. Clean and plugged in properly? Retest, work? Problem solved.
Get a multimeter and touch the two prongs with the meter probes. If the switch is working, there should be continuity when the button is not pressed. With the button pressed in, there should be no continuity. If broken, replace the switch, otherwise replace the bulb.

[DmbShn41]

OP, had similar issue with that exact switch. My rear brake switch would work, front brake switch didn't work, mechanically it worked, however when I removed it and put a meter to it, state didn't change. Believe that switch is a normally closed device. Partzilla, eBay, etc about $10.

[Whiskey]

The front brake light switch is well known for being easy to break when you're switching out levers. the 'button' on the front can get snapped short.

first things first check the bulb.