Topic: Tail light help!

[Pirate Gonzo]

Hi everyone. I bought my CB550 with a Sparto Tail Light Assembly already on it. With the key in the on position the tail light does not come on but the brake light works. If I turn the key one notch further to the "parking" lights then the tail light comes on. This is probably something stupid that I am missing but if if anyone can give me a slap in the face of what I am missing I would really appreciate it.

http://www.oldbikebarn.com/part.php?id=814&subcategory=Tail%20Lights&bike=&DisplayPerPage=20

[ProTeal55]

Obviously it is something with how the taillight is wired.
It seems as if the "parking/running light" is not getting power untill the 2nd click of the switch , as you stated.
I would trace the wires, and see where the previous owner grabbed the power from for that fillament.

It can be fixed, just a matter of tracing wires.
Isn't electrical fun 

[jdpas29]

hahaha  i had the same problem with my 78 750K.  i just rigged it to where my bike runs in the "all the way over to the right" position all  the time.  works great.  it was the only way i could get the brake and running light to work at the same time.   

[sadams1954]

I guess the question I have is whether the headlight is burning or not? On my bike, if I forget to set the headlight switch to the ON position, my taillight doesn't burn either.

Steve

[TwoTired]

The ignition switch and switchology varies with year and model of the CB550.  Some of the earlier models needed a jumper on the back of the ignition switch for proper tail light operation.

If I knew which year and model you have, I might have better info for you.

Good luck!

[Pirate Gonzo]

Ya, I suppose I could have offered a bit more info on the bike. It is a 1976 CB550. According to the Clymers book the wiring that is at the back of the bike is correct. I did trace the brown wire to the ignition and it is connected to position 1 and 2 on the ignition. The wire is not broken. The tail light has a black red and yellow wire coming out of it and is an LED circuit board type. I thought that maybe position 1 on the ignition is possibly bad?

[TwoTired]

Makes a big difference if you have an F1 model or a K2 model.  2 Very different ignition switches, and different wiring harnesses.

If you have the stock wiring over the rear fender, green is ground or battery minus, brown is the run light power +, and G/Y is the stop lamp power +.

Your aftermarket tail lamp follows whatever convention suited them.     Often black is ground.  But, with the Honda wiring, black is Battery plus after the ignition switch.

Let us know if you have an F or a K.  And, how much of the bike's electricals are stock.

[jdpas29]

being that it's after market.... i'm just gonna guess and say that the red wire is the hot wire for the running light, the black is the ground and the yellow is the brake light.  in any event the black is probably ground so switch the other two if need be.

also...  err on the side of leaving your ignition switch itself alone for now.  work with your grounds up in the headlight box (if a 550 is anything like a 750). 

question... with the key in the park position, does the headlight come on with the running light?  in the 'on' position does the headlight come on while the brake light will work?

this thing can be rigged, bro!   

[Pirate Gonzo]

Ok, I have a K model. The wiring for the tail light is all stock. The headlight does not come on in the park position. I took the tail light and touched the wires to the battery and the Yellow wire is the running light being the dimmer and the red wire is the brake light being brighter.

[Pirate Gonzo]

NEVERMIND, I have walked into a well hidden electrical tape nightmare. Ha, ha, All black wires some hot some not all hidden by the plastic sheath. I'll let ya know what I find.

[Pirate Gonzo]

Well, after finding all the broken wires I took the entire ignition apart and removed all the spliced wiring. At the ignition there was about 3" of original wire and about 3" at the plug. All the wires were spliced with black wire and it was all twist and tape. After I removed all the crap wire I found that the brown and brown with white stripe were loose from the solder on the ignition so I re-soldered them back tight. I then soldered the original wires to each other and mounted the ignition on the frame with a U bolt. Fixed the problem, I now have a tail light and now when I have the key in the position 2 "Park" the head light comes on.

This is my temporary fix until I can find a new/used ignition to replace it. I found some on ebay but I want to know if there is any place that sells them with the matching seat lock? I don't want to have two keys for the bike.

So if anyone has any connections of where I can get one or if any of you have a match set that I could buy I would appreciate it.

Thank you.

[jdpas29]

u-bolt???  is your ignition housing broken?  when you say ignition, are you talking about the box up at the handlebars or something back near the middle of the bike? 

also... i have two keys.  one for the seat and one for the ignition switch.

[Egil]

You may tray to get some parts from CMS in Holland (Netherlander) the address are http://www.cmsnl.com
 they take a searts(the world) and find if there is anyting to find  ` If they don`t have you have a problem   

The next step are the after marked !

Hope you have can been helpt

[Bodi]

The stock tail light circuit is mega-strange. Impossible to explain simply.

To try... in order of connections... from memory...

Ignition switch ON:
Battery  - (red wire) - MAIN fuse - (red/black?) - igition switch - (black) - headlight on/off switch ** - (brown/white?) - TAIL fuse - (brown/blue?) - back to ignition switch - (brown) - tail light socket

** headlight on/off - available where laws allow, if no switch like on on US and other models there's a wire splice in the right switch cluster harness connecting black and brown/white (?) wires.

Ignition switch PARK:
Battery - (red) - MAIN fuse (black/red?) - ignition switch - (brown) - tail light socket

So in PARK the tail light doesn't use the TAIL fuse. In ON it does. To me it looks like your wiring has been butchered a bit, but you should be able to figure something out. The usual problem is with that headlight ON/OFF switch, make sure you have the ignition switch wired to spec and then check if you have voltage on the TAIL fuse with ignition ON. If not, check where the right handlebar switch cluster connects to the main harness, you might find a lonely brown/white (I think) wire in the main harness not connected to anything. This happens when otherwise identical non-original switch clusters are used, the wire spliced to black isn't there. Jumper the brown/white to black (check a proper Honda wiring schematic to make sure of the color).