Advice please on speedo

Ok I'll try and break this down short and sweet...

A few months ago I had my front tyre changed and the speedo rotor fell out of the wheel in several pieces. I ordered a new rotor, fitted it and voila problem solved.

A few weeks ago, my speedo began throwing out random speeds and then gave up the ghost and just reads zero now. I assumed that the rotor had gone a second time and subsequently ordered a new one at £17.

Come to fitting it and it turns out that the rotor was still intact. Tried cleaning the speedo housing and putting it all back together had no effect. I've since tested the speedo sensor with a circuit that the Haynes manual suggested and it does look to be faulty from the readings it gave (either that or it could be my dodgy soldering).

The dilema I have is that the shop wont refund the rotor (£17) but they will credit it against a new sensor (£102). I have found a sensor from a salvage company for £35 but my worry is that this could cause me more problems. Is it worth paying £50 more to get the whole new unit or do I save the money and take the risk of a second hand one.

I guess the real question is how often do the sensor units fail. Is it common?

I have one out of my curvy 02 which im selling, it worked spot on before i changed my front end. pm if your interested...
as for the sensor.. they do go.. but not very often.
what do you mean about your dodgy soldering? what part of the wiring have you modified?
cheers
dan

Originally Posted by DionysusVii

A few months ago I had my front tyre changed and the speedo rotor fell out of the wheel in several pieces. I ordered a new rotor, fitted it and voila problem solved.

So as I read it, all of this *might just* be the fault of the people who fitted your last front tyre?

I'd be having a quiet word with them, myself.

Ahh, thanks Dan but after sleeping on it, I think I'm just going to bite the bullet and get a new one. As for the soldering, that was just a tester circuit that I built with 4 batteries, a resistor and a voltmeter under the guidance of Haynes manual.

Hopefully the problem IS the sensor and not something to do with the digital dash.

[the_lone_wolf]

some people had funny speedo gremlins when their batteries were going didn't they, not sure if it's relevant?

Ahh bugger... this is getting really annoying.

I decided to buy a brand new sensor which I replaced a 2 weeks ago. Worked as soon as I connected it and has worked for 2 weeks. Then suddenly on Saturday I get the bike out and its reading zero again

I've had the wheel off just to check the rotor and thats all ok. So, has the new sensor gone again or could it be something else? If its not the sensor then why did it work immediately on changing it? I've checked the wiring where the sensor connects to the loom and that seems ok.

I'm at a loss. Any ideas?

Any help would be greatly appreciated.

[the_lone_wolf]

checked your battery? reg/rec?

Sorry, excuse my ignorance - reg/rec?

I checked the battery with a voltmeter and thats fine though

[the_lone_wolf]

Originally Posted by DionysusVii

Sorry, excuse my ignorance - reg/rec?

I checked the battery with a voltmeter and thats fine though

regulator and rectifier

basically turns AC from the alternator into DC for the battery

if the battery voltage is OK it probably isn't that, just a thought...

Right, I see.. thanks anyway.

I wondered if it might be a connection problem between the connector of the speed sensor and the digital speedo at the dash. I applied the volmeter to the 3 pins and got a voltage of 10V on one and 4V on the other so I'm assuming thats ok?