speedometer odditity Parts diagram calls it a Lead Switch 34860-45110

[Guest]

Replacing my speedometer, and this part have me puzzled. I have tried to find by searching part number and description, but I found nothing.

What does this part control 34860-45110. It attaches into the speedometer like a light bulb and appears to be made of glass.

[Steve]

For many things, the Japanese/Engrish tlansrations were a bit "interesting". Witness all the entries for front and rear Caripers on the brakes fiche. Several other examples can be found.

I think this is another example. It is actually a REED switch, which is part of the auto-cancel turn signal system.

Inside the speedometer/odometer assembly, the cable that comes from the front wheel spins a magnet on a disk. That disk spins inside a cone that is dragged by the spinning magnet to move the speedometer needle. (I might have that reversed, it might be a magnet on a cone, which drags a disk to move the needle.) The REED switch is simply a magnet-activated switch. It is mounted near the cone (or disk) that is rotated by the speedo cable so it can sense the magnet. As the rotating magnet comes by, the switch is momentarily closed, which sends a pulse to the TSCU (Turn Signal Control Unit). The TSCU is looking for a speed of over 10 MPH for more than 10 seconds, after which it will turn the flasher OFF.

The switch is not needed for 'normal' operation of the bike, it only affects the auto-cancel system.

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