Red Brake Test Light Stays On

[tweather]

About a week ago it happened for the first time, but only stayed lit for a few minutes before turning off during my drive. I, foolishly, hoped that it had "solved itself."

From what I can tell, all of lights are operating properly. How concerned should I be? Any ideas what might be causing this? I need the red light of shame to go away so I can ride with full attention on my surroundings, instead of wondering what is causing the bright red light in my peripheral vision.

[Laitch]

Carry spare brake light and tai light bulbs, learn how to install them then keep riding.

[tweather]

Maybe I'm missing something, but that doesn't seem particularly helpful. :dunno2: I do carry extra bulbs, but they are all working properly and don't need replacing.

I was hoping to find out why the light has begun to remain on after depressing both brake levers.

[rbm]

The BMU light is saying that a bulb is burnt out.  This could be a broken filament but it could also be a poor socket connection; both produce the same results.  However only one fixes itself - guess which.  You should be investigating why the bulb does not make good contact with the socket.  I have read forum posts that talk about modern 1157 bulbs not mating well with the European sockets on the K-bike but I can't find a reference for you right now.

[Laitch]

Maybe I'm missing something, but that doesn't seem particularly helpful.

  :musicboohoo: It's hard to find good help sometimes at these rates, tweather.
You can always put tape or one of those cheerful children's band aids over the light; otherwise—following on from RBM's helpful post—you might try cleaning the unit's contacts. You can read a description of it starting at item 2. there and more about it here.

[tweather]

Laitch, you're totally right. Thank goodness for those nice guys up north, eh?

Thank you (both of you) for your help. I'm not well versed at diagnosis, but I do like working on my vehicles myself. This was exactly the information I needed.

[Laitch]

Laitch, you're totally right. Thank goodness for those nice guys up north, eh?

Most everything's north of you, tweather. Good luck.

[Brad-Man]

I think you both need to be reminded that there has been good help from people WAY South of NA...

[Laitch]

I think you both need to be reminded that there has been good help from people WAY South of NA...

Good point, Brad-Man. I nominate you for the MOTOBRICK.COM Chair of Inclusivity.

[Brahma]

Check your rear brake light switch- they have to take a lot of abuse in that location.  Flush it with a few spurts of wd-40, but it might be toast.  I've replaced several over the decades.

[tweather]

So, it was brought up that I didn't clearly resolve this thread.

It was a poor socket connection. The socket had been deformed by a higher wattage bulb overheating the socket and causing poor contact. I replaced the bulb and socket.

No more red light.

[Chaos]

Mine hasn't worked for so long it took a minute for me to figure out what you were talking about.  Fortunately, my warning light stays off.  Could be the first stage of the ultimate demise of the machine, at this rate it will still outlast me. 

[Laitch]

Thanks for the update, Tweather. It's likely more than a few wiring problems have been cause by out-of-spec bulbs.

The bulb monitor feature has been helpful for me a couple of times while riding and I'm glad I have it. If it ever fails and can't be resuscitated, I'l buy a Motogadget and start a long chain of queries to rbm. :giggles.

[84K100RT]

It comes on solid if

A failed bulb. replace it.....
A poor connection at the rear light or brake light bulb. Clean it up.
A failed/faulty front or rear brake switch. Replace it.

On the K100 4 valve the brake switches and clutch switch are interchangeable.

It flashes if its an ABS fault.

[jay1622]

Figured I'd add to the thread with the following for those who stumble upon it in the future...

To test the brake light switch/circuits...

Test the brake switch(es) by disconnecting them at the connector and use a multimeter to confirm the presence/loss of continuity as the switch is engaged/disengaged. Obviously, you're testing the connector on the wire attached to the switch, and not the connector on the wire that leads to the wiring harness. Remember, the switch may behave differently if it is installed in their respective locations, as opposed to being removed and manipulated by hand. DAMHIK.

Test the particular circuit controlled the respective switch by creating a jumper and closing the circuit at the wiring harness end of the connector.