Topic: CB750K K7 unidentified wire

[Erny]

After replacing steering stem bearing and front end cleaning, I just started to re-connect all electrical connections on the bike front (in the headlight) and found 1 wire I'm unable to identify where it belongs to.
It is brown/white wire coming from combined turn/light/horn left handlebar switch , most right on attached picture.
Checking wiring diagram there should be no such wire??? (diagram attached). Diagram is from original owners manual and the same is in shop manual (K7 supplement info part). Diagram shows 10 wires but I have 11...

Bad is that wire was connected somewhere (has scratches on connector) but no idea where..

Does anybody have any info about it? Bike is K7 (model 1977), manufactured 10/73, all original.

Thanks

[Johnie]

That wiring diagram shows that wire marked Br/W.

[Paintedseat]

Is it not the turn signal buzzer

[Johnie]

Back when I had a K7 I do not recall a turn signal buzzer on it. Looks to me like it is going to a lamp. Maybe a turn signal lamp on the dash?

[Flyin900]

There is a brown/white shown on the gauge cluster lighting on the diagram, so do you have those wires connected to your gauge cluster lighting connected to a 12V source?

This is another possibility if there is no apparent connection for that wire on your bike

I went through the same thing recently when I substituted a left hand signal/headlight switch from a 1976 Goldwing to a CB400F that I was doing. I wanted the clutch perch that was part of the switch on the Goldwing switch assembly and there were two extra wires in there vs the original CB400F switch assembly. One wire was for the turn signal buzzer used on the 76 Goldwing and also on some early CB750's too.

So unless your the original owner of this bike from new chances are some PO substituted that switch onto your bike and the scratches are from when it was supplying a service to the correct bike it came from originally. Just tape it off if you can't see a use for it; as I did that on the CB400F and every circuit and accessory works correctly with only the original wires connected properly. 

[Johnie]

Sounds like a good plan to me.

[Mr. Mike]

Yep,

Check your speedo and tach gauge lights in the dark, looks like it might be it (according to the online diagram compliments of Oregon Motorcycle Parts. My ‘78 CB blinker buzzer is Br/Bl. The wire being a male end, check your tail light too.

[Erny]

Speed and tacho are ok, have power.
This wire looks like as redundant. Hard to believe that PO chaged switch, bike has only less than 9000miles

[Phinn]

The 77 and 78 have an unused connection up front. For some accessory that didn’t get into production.

[Airborne 82nd]

The 77 and 78 have an unused connection up front. For some accessory that didn’t get into production.

I think that was for a parking light on top of the headlight shell not used on USA bikes,

[Erny]

No it isn't. Parking light has the same connector - male. Other end should be female...

[Jerry Rxman Griffin aka MuthaF'er]

Do I see a black wire in the back ground with brown and white bands? Or is that orange and white?

[rotortiller]

The Brown/White from that switch goes into a female multi connection bullet connector.

There is also another jumpered Brown/White multi bullet connector in the headlight bucket with a brown/white with black band with black wire crimped to it. Instrument lights go to this one. If you want look at the pic it follows the 1977 wiring diagram for the jumper.

[Erny]

Mystery solved today - that wire should be connected to brown wire from main cable bunch coming from back of the bike in order to power position lights in front flashers
This connection is not at all shown in wiring diagram...brown connector is shown as not used.

Anyway thanks for help

[Stev-o]

The 77 and 78 have an unused connection up front. For some accessory that didn’t get into production.

I thought for sure it was the optional CB radio!

[Can550]

European headlight version used it 


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[Phinn]

The 77 and 78 have an unused connection up front. For some accessory that didn’t get into production.

I thought for sure it was the optional CB radio!

It was for the combo CB radio/GPS/Super-computer system. Like on Captain America’s motorcycle. A very rare upgrade.

[robvangulik]

European headlight version used it 


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European bikes have no position lights.....not in the 'flashers' , but they do have parking lights.

[jgger]

It's an underwire for a bra, did you misplace the Victoria Secret model that it was connected to?  That's why you should label everything as you take it apart.

[PeWe]

Open switch and see where it is connected and how it will get 12V. I did that with all wires before connecting them when I restored my K6. Marked each wire with tape from both controls and matched them with main harness.