brake light help

[cmichael]

Need a little help as my bike is not with me at the moment.  I am attempting to clean up the po's wiring job and need some clarification.   On the pic with the three wires, brown is ground, which of the other two are constant vs switched?   On the other pic, the two wires coming out one is constant one is switched, does it matter which one I use?  The side tang is ground correct?


Thanks in advance, chris

[Grim]

On the bulb on the right you have dual filaments. One will be a running light the other will be a higher wattage (brighter) for a brake light. So yes you need to figure out what one is the brake wire. I haven't messed with my bikes brake lights yet but most German vehicles are pretty consistent with color codes. I would think it will match the harness going to the swtiches at the brake lever and foot brake.

Tommrow I may have a few minutes and will see if I can meter my bike and let you know what is what if somebody doesn't beat me to it tonight. You might also look in the the section with the shop manual and see if there is a schematic and it should list the color codes.

[kioolt]

I was thinking that BMW K-bikes uses a single filament bulb.  There's one single filament bulb for the tail light and another single filament bulb for the brake light.  Can someone correct me if I'm wrong?

The brake light socket in the picture appears to be non stock to me.  Is there a single filament bulb in it or a dual filament?  I'm thinking its got a single filament with a dual contact base.

[johnny]

greetings...

about IMAG2355.jpg

the one on the left is the tail light and it uses a 5007 single filament bulb available at any autoparts store... the one on the right is not oem to your motobrick so its hard to say what the he11 is in there...

j o

[cmichael]

After a little research it appears the po installed run-n-lights.  So I really can't blame him for the crap wire job as he bought this as a kit :yow

Now to clean it all up!

Any info on the 3 wires would be cool, clymers and bike are at work and I dont want to see that place until I need to.

[kioolt]

I can't tell much from your picture on the three wires, but the factory wiring would be as follows.


Blue/red tracer - Left turn signal
Blue/black tracer - Right turn signal
White - Tail light
Green - Brake light
Brown - Ground

[Grim]

Well I looked at mine and apparently Mr Wizard has visited me as well and added three LED's (two not working but are hidden in the housing so I didn't see them before).  :dunno

I do think I know what your PO has done and his reasoning.

As BMW wired it you have the lower bulb (Left in your picture) as a running light and the upper bulb (right in your picture) was a single filament brake light.

What your PO did was put a dual filament socket and 1157 bulb in so that the whole light would be lit as a running light like most cars. I can see his reasoning to have more area for better visibility. The only real concern I would have is most cars when the brake light comes on the lower wattage filament goes off to try to prevent the bulb over heating giving short bulb life and possibly melting sockets made with plastics.

Metal socket may make melting a non issue just keep spare bulbs and check your brake lights frequently.

To put it to stock you will need to get a single filament socket and remove the jumper to the lower bulb.