Headstock Electrical Component ID

On my ‘83 XJ750-EII, on the front of the headstock between upper and lower yokes (but nearest lower), there is a plastic quadrant around which a metal “tab” moves. This component has electrical cables that terminate in a plastic block which ultimately end up the instrument binnacle.
I can’t seem to find any mention of this thingamejig anywhere or find it on a wiring diagram. I’ll try and upload a picture.
Any ideas anyone ?
Cheers
David

 

Wow, very odd. Does this gizmo perhaps move as the forks are operated (rotated)? Could it be a version of the flasher cancelling mechanism?

 

contact member
Garries
he may have a copy of parts manual he got from
z32800


https://xjbikes.com/forums/threads/1983-xj750-e-ii.46092/
↑

 

Yes, it moves as the handlebars are turned. Indicators are cancelled in the usual way, by pushing the turn signal button !

 

Well, most XJ (and others) of that era had a self-canceller module (electrical), a sort of time/distance "computer" (but no chip) within the electrical system that provided "automatic" signal cancellation:

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TURN SIGNAL RELAY ("FLASHER") and SELF-CANCELLER:

tsrs1) OEM turn signal system FLASHER and SELF-CANCELLER RELAY. In order to design a "self-canceling" turn signal system, Yamaha chose to use a simple but very different style turn signal Flasher than what is used in almost all other vehicle applications. Of course, the unique design of this flasher unit makes it, let's say, "pricey" to say the least! However, if you want your self-canceling feature to work then you'll have to use this original flasher. NOTE: many aftermarket mechanical or solid-state flashers will not function (at all) in place of the original flasher, and even the ones that do (see below) will disable the use of the self-canceller feature from operating.

Also, if you substitute LED bulbs in your turn signals for the standard incandescent bulbs, then the stock flasher (which is mechanical) will not see enough of an electrical load to be able to flash correctly, if at all. In such a situation, the stock flasher is not defective, it is just designed to operate at a much higher voltage draw than LED lights provide, and you will need to replace the stock flasher with an aftermarket solid-state flasher. NOTE: the use of most aftermarket, solid-state flasher relays will defeat the self-canceller feature of the original system.


Identification: The FLASHER is contained in a large, rectangular black hard-plastic "box" housing, and has the following 3 wires connected to it: a solid brown wire, a brown wire with a white tracer stripe, and a yellow wire with a green tracer stripe. This applies to all models except XJ700 and XJ750-X models.

The SELF-CANCELLER UNIT is a rectangular, sealed, rubber-coated box with 6 wires coming out of it into a connector: a solid tan wire, two (2) white wires with a green tracer stripe, a yellow wire with a green tracer stripe, a yellow wire with a red tracer stripe, and a white wire with a red tracer stripe.

By the way, the self-canceller operates off both time AND distance measurements to determine when it should cancel the flashers.....a minimum of 10 seconds time and 150 meters (about 400 feet) distance. BOTH criteria must be met before the canceller releases the signal flasher:

http://www.xjbikes.com/forums/threads/help-with-automatic-cancel.81440/


NOTE: the signal system is designed so that it will still operate if the self-canceller module fails; of course, in such a situation, you will have to cancel the signals manually (by pushing straight “in” on the thumb lever after it has returned to the center position). To diagnose problems with your signal system, you should follow these steps:

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So what you may have is a "pre" self-canceller mechanism there, when the signals are set to flash, they are "cancelled" via the movement of the forks to-and-fro within that mechanism, which sends an electrical signal (or opens a ground path) and thus "cancels" the operation of the flasher relay. In essence, this is also what the later-style "self-canceller" module does.............although it uses wheel rotation counts and time counts (rather than mechanical fork movement) to determine when the electrical cancellation "signal" is authorized/sent to the flasher relay.

Also notice that both your system and the later self-canceller system operate electrically ON THE FLASHER RELAY, rather than mechanically on the sliding terminal contact plate within the left-side handlebar control switch. Pushing straight "in" on the signal thumb-lever will mechanically disconnect the flasher circuit within the switch, by mechanically moving the electrical contacts apart from each other. Note that the "automatic" self-cancellers do not perform this function, and, if you read the owner's manual carefully, you will note that Yamaha recommends that the thumb-lever should always be pushed in after turning is completed (whether auto-cancelled or not) as a way of self-centering the internal switch terminal plate. Yamaha did not want you going from full left to full-right positions on the sliding mechanical plate within the control switch, as that tends to wear out the contacts and the mechanism. However, if you let the self-canceller perform all the work, then periodically you will be making/forcing the terminal plate from full left position to full right position (or vice versa).............when you select, for instance, the left turn signal, with the thumb lever, as soon as you release the lever it snaps back to the center position, but the internal contact plate remains "stuck" in its far-left contact position (it must, in order for the left signal flashers circuit to be connected to the 12V power source). So even when the thumb lever snaps back to center, the contact plate does not. And eventually, when you next select a right-hand turn with the thumb switch, you are forcing the internal slider plate to move from full left lock, past center, to full right lock.......and it is this operation that Yamaha wants you to avoid doing. And since the self-canceller is an "electrical" grounding of the flasher relay to cease the circuit (flashing), it does not/can not mechanically "center" the mechanical works within the switch housing. That must be done manually, by your thumb, pressing inwards on the thumb switch, which releases the contact plate to center itself again.


Anyways.........if I were you, I would try to find and buy a few spares of that switch, as it looks kind of fragile, and I doubt that they are very common anymore (if they ever were to begin with)..........

 

Thank you. It is not the self-cancelling “Block” as I have that too !! I’ll try and find out where wires terminate

 

Hmmm. Well then. I thought it was a darn good theory! And, in fact, it still may be..................remember, the later (?) style self-canceller requires two inputs: distance travelled (via a reed switch in the gauge cluster, connected to the speedo drive gears, thus "counting" how many wheel rotations are made, thus equaling a distance travelled) AND a time factor (this is done electrically via some type of black-box magic that I won't take the time to describe). Perhaps your bike also uses a self-canceller module, but it is set up to take FORK MOVEMENT (to-and-fro) as one of the input factors (instead of distance travelled) as well as the same TIME factor.

I cannot imagine what else a sensor that records fork movement would be used to "control" or report upon.........

 

Im with chacal, it must be part of the cancelling relay system, it only makes sense.
These options were unbileavibly complicated for there time.
My 85 XJ for example has the "reed style" signal cancelation system.
As far as i understand, it works by using a bi-metallic strip, that gets hot with voltage applied, therefore bending and releasing contact under certain conditions.
Observations: If idling, the signal operates continuous, when rolling away from an intersection gently at low rpm, it will turn off in a while, if accelerating moderatly, the signal turns off sooner, if you wail on it right after turning... The signal allmost allways shuts off as soon as you hit 5000+ rpm.
I assume therefore that at higher rpm as the stator produces more voltage it therefore heats the bi-metallic reed sooner and cancelling the signal faster.
A mechanical system, but very complex.
Of course this only activates a relay system and isnt directly connected to the signals.
Said system may also rely on speed signals that im not aware of.
This may not help you fix your bike but explains how complex some ols stuff can be for thier time without computers.
Btw.... I hope im not wrong on this fact... Hehe

 

Thanks Colin, talk about a hammer to crack a nut !!
I have read that, for the Japanese market only 29R model, the R stood for Research as they designed and fitted a number of options that complemented the instrument warning system on the basis that they might carry over onto more mainstream worldwide motorcycle variants.
Not sure if that’s true or not.
AFAIK my bike’s systems all work correctly tho I’ll find out for sure once I’ve finished the resto.......give me about 6 months !!
Cheers

 

Is there a way to get a wiring diagram for the bike? That would indicate anything with wires going to it. You can also track the wire color up the harness to see where else it connects.

 

I’ve got a couple of WDs and will check cable colours tmrw but certainly the WDs I have don’t indicate anything like this component.
All very strange !

 

Yamaha typically used the R suffix to denote a sports oriented machine. They also put a lot of different features on the bikes they made during the 80's; even going so far as to have entirely different electronics components to do the same job on different models, while having the same parts do the same job on others.

The bit you have on the headstock does look like a signal canceling switch that I've seen before. I just can't remember on which machine, it's been so long ago.

 

I checked the wiring today, there are 3 wires that terminate into a plastic block : red/white, blue/white & black. The other side of the connector then runs into the back of the instrument binnacle separately to the main 2 loom bundles.
I haven’t got further into the binnacle yet.
There is nothing like this on the numerous wiring diagrams I possess.

 

what color are the mating main harness wires?

 

Same !

 

On the Maxim 750 and Seca 750 part of the self-cancelling system resides in the speedometer (the distance check).
Dig deeper. The solution is near I think.

 

We WILL solve it ! Thanks all

 

this may help


YAMAHA Genuine Used Motorcycle Parts List XJ750E-II Edition 1 29R 537

https://www.ebay.com/itm/YAMAHA-Gen...=item41f18c30d3:g:fvUAAOSwRUdbl40F:rk:11:pf:0

and this service manual
https://www.ebay.com/itm/YAMAHA-Gen...=item41f18c2a7c:g:7FsAAOSwSflbl40-:rk:18:pf:0

 

Hmm, won’t send to UK !!

 

if you can unplug the connector ohm it out.
you will see if it acts as a variable resistor or as a switch.

ohm from black to B/W and Black to R/W also try from B/W to R/W.