1982 KZ1000k ltd speedo speed sensor failed. Repairable ?

KZ1000k 1982 electronic speed sensor seems to be doa. Are these things repairable?If you look at the attached picture you will see a hex bolt like fitting at the point where the wires go into the housing. Has anyone tried to open these sensors up ? Is there a three terminal hall sensor that can be replaced inside the housing ?Thanks

I think I have a "take off" from my Mrs' upgrade last year. Where are you? You can have it if you're local to 95240

Thanks for the offer slayer61. I'm about 1300mi north east of you. Seems the PM feature doesn't work anymore ??
I would really like to see what's in these sensors. If someone could post a pic that would be great.

Check the wires where they come out from the sensor. When mine played up it was because it had a broken wire which intermittently connected or not.
There's not much that can go wrong internally with the hal sensors they are just magnets generating electronic pulses. 

If it's not the wires it'll be the drive disc.  If the spindle nuts have been over tightened the drive disc gets deformed and doesn't rotate smoothly giving inconsistent pulses making the speedo needle fluctuate. The angles of all the joints MUST be at 90 deg to stop any needle fluctuations. 
Tube to disc plate = 90 deg. 
Plate must be flat and not domed. 
Plate to drive prongs = 90 deg. 

Any one not true will mess with the pulses. 
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Thanks Warren
All three wire seem to have continuity. With meter set to diode mode all wires have either diode characteristics or a resistance. No shorts.
It was my impression that a hall sensor is an electronic device not a magnetic coil. When connected I get 12v across the white and yellow black wires.
So the hall is getting power from the odometer box. But no pulse of the bluish wire. I checked the speedometer drive on the wheel. It is there and square and
is smooth driving the speed sensor. Of course I cannot see what is inside the sensor. What is the hex bolt like thing where the wires go in ? Looks like this could be removed.
Has anyone tried to remove this ? I was afraid I would break something so I didn't touch it.
If someone has a dead unit could they try to remove the wire connection and post pictures ? thanks

Have you tested as per the FSM and what results did you get 

Silly question but I assume the  "hooks" on the drive are not misshapen and are engaging the hal sensor pins. It's quite easy to assemble the front spindle and not engage the drive to the sensor. Done it myself a couple of times. 

Yes all the wires are connected and power is there.
Well it is kind of hard to see if the drive sleeve is actually rotating anything inside the speed sensor. 
The sensor engages the sleeve and rotates smoothly.
Interesting the manual shows the internal gears in the mechanical speedo drive but not a thing of the electronic one ?!?!
Hall sensors are usually three terminal devices with power and ground and pulse output.
Anyone actually try to remove the hall sensor assembly ?

kz650guy123 wrote:

1) The sensor engages the sleeve and rotates smoothly.

2) Interesting the manual shows the internal gears in the mechanical speedo drive but not a thing of the electronic one ?!?!

 

1)  with the sensor off the bike and the sleeve engaged test to see if you get any variations in multimeter readings as you turn the drive. Hal sensors work by fluctuating the resistance with a magnetic field.

2) that's beacuase they are non serviceable. Bar a loss of magnetism or not rotating the magnets there's nothing that will stop them working. 

I suspect your drive sleeve is the issue not the sensor. 
Post some pics of both components from several different angles. 

The sensor is engaging the sleeve and seems to rotate smoothly. I have no way to know if the internal magnets are rotating.
The sensor is not outputting a signal at all of any kind. And yes plus and minus 12vdc is coming to it from the odometer box.

Why would there be a hex nut/bolt where the wires go in if it was not intended to be removed ?

I disagree. All hall sensors I have seen are three terminal semiconductor devices. They require power and output a signal. Some output a digital signal 
and others output an analog signal. Since this is supposedly a hall sensor and not just a magnetic pickup coil. All semiconductor devices can and will fail.
I don't have a picture of the sensor receiver sleeve right now. It looks exactly like the one in the partzilla diagram. Just like the sleeve that runs the mechanical drive. It's not deformed in any way.

All the clever bits are on the speedo pc board.
With it off the bike you should be able to put 12v+ into it, with an ohmeter on the out wire to the neg. Rotate it and you should get a fluctuation in resistance. If you don't it's not being rotated by the drive. 

A lot of things have happened since the last post.
I did find out that the speed sensor was rusted and locked up.
So I got another sensor. This one rotates and when I manually rotate it the odometer box does move.
I got a new receiver/drive sleeve also.  Thought it was damaged. lt Didn't look any different than the old one.
Still doesn't seem to rotate when installed. Seems to bind and keep the wheel from turning freely.
I can't get my photo editor to put alpha text on the photo. It did put a blue line where measured.
So I measured the drive slot in the sensor 22mm. 
The drive sleeve part that should go into the sensor slot seems way too big. 27mm It could never fit in there.
That's why it's binding.
So am I going crazy here ? Or are there different versions of drive sleeve for electric sensors ?
Can someone help me here ?