Topic: Emgo CB750K0 wire harness

[lash]

I have only one problem after all the wires have been hooked up I think and that is confusing the hell out of me. I have a working brake light and I have a working headlight/taillight. The problem is when I turn on the headlight, my brake light no longer works. There are only 2 wires not hooked to anything in the head light bucket, a black which is coming from the brake circuit and a brown that shows continuity to the tail light, As the brown is not connected to anything in the bucket the tail light must be getting power from somewhere else like the ignition switch?
Other thing is I only have a single 15a fuse on the red wire from the positive battery lead. Is this correct for a 69?

[Bodi]

Black is always fused ignition-on power, the brake light wire should be green/yellow if it follows the usual colour code. The brakelight switch should have a black and green/red wire to it. I can't see how the headlight on could disable the brake light but somehow it does for you.
The brown is the tail light power, some headlights have a small bulb for a parking light - with the key in "P" the tail light and - if it's there - that bulb come on. These should come on with headlight on and in "P". The keyswitch wiring is probably a bit complicated to do this trick.

[RAFster122s]

First word is your first problem according to many...
I presume your 69 K0 is a CB750? Did you compare your old harness to verify the wiring in the bucket matched and the colors were all correct. Where is the front brake switch wiring connected and the rear brake light? Are they joined? In the harness? When the key is on and you activate the pressure switch or rear brake switch are you getting power on the brown line?  Does the brown and black connect in the headlight bucket?  What does your wiring diagram show for the brake circuit...

Is your ignition switch functioning correctly?

[lash]

Had a quick troubleshoot this afternoon and the problem is in the taillight itself. I didnt have time to go any farther and won't until after the weekend. I will try and report back what I find. Thanks for the replies.

[Don R]

 An  internally shorted bulb will make a guy crazy, change or at least check, it just in case.

[lash]

It's working now. The wires from the original taillight are green, black and red/blue. With r/b to green/yellow and the green to ground, black to brown on the Emgo harness, I was having the problems. I swapped wires around and finally found that with the green to black and the black to brown the problem is gone. Old bikes are such fun!

[Johnie]

Yes, the single 15A fuse is correct for the 69 & 70KO.

[beemerbum]

Yes, the single 15A fuse is correct for the 69 & 70KO.

As well as for the 1971 K1

[lash]

I did not have the original harness to compare anything to but everything seems to be working correctly now. Next electrical will be the points I think. Thanks for the replies..