wiring- digital speedo unit -help with the sender

[oberonspacefr...]

hi chaps

ive bought a digital speedo/tach unit, that has a non cable drive speedo.
i bought it, as the bike hade an expensive koso unit that sells for 150 ish, and it as missing when i bough the bike.

at the moment, the original sender from the front wheel has 3 wires, but the reciever from the display unit only has 2.

bit worried about using the process of elimination method, incase i burn somthing out.

anybody had any experience with these? i dont know what is physically happening at the front wheel end......

[Andy_Pagin]

I can only speak for the Fazer sender. At the wheel end it's just a 'top hat' tube that latches to the wheel with a sleeve over it attached to the fork, that bit has the wiring. The top hat appears to be made out of something like Bakerlite and I assume it works by some form of electromagnetic induction. So there's not a lot that can go bang, or generate enough current for banginess at the instrument end.
____________________
They're coming to take me away, ho-ho, hee-hee, ha-haaa, hey-hey,
the men in white coats are coming to take me away.
Yamaha Vity -> YBR125 -> FZS600 Fazer -> FZ1-S Fazer

[mudcow007]

like a reed switch imagine, similar to what is in a pedal bike speedo.

As the magnet passes the switch it opens, when the magnet moves away it closes?

[Meatybeaty]

What make is your bike and what make is the new clock set

[WD Forte]

I've fitted quite a few but as you've made such an effort to supply
such vague and minimal information, I won't go and spoil the long, drawn out, teeth pulling, guessing game you've invited.
____________________
bikers smell of wee

[oberonspacefr...]

Thanks for the help chaps. It's a megelli bike and a koso copy Speedo head unit. The unit has a top hat as described within stick on magnet. I'd just fit that but it's much flimsier than theone already fired which is an integral part of the brake caliper
The old one has three wires the new one has two. If it's just a breaker switch I'd expect 2 wires so I've got to decide which to lose. Presumably if it's just an opening switch at wheel end I won't do too much damage with the trial and error method
Would photos help?

[Meatybeaty]

Hi , yes photos would help, have you got the original wiring diagram for the original clock set, you might be able to step back and look at the wiring set up and take it from there, the original wiring diagram would show how and what wires (if different colours) were joined to the existing loom