speedo needle jumping

[HovBiker]

My speedo needle recently started to jump around.first noticed it when I turned indicators on.it's only intermittent but driving me nuts.anyone got idea what may he causing it and is it easy fix.cheers.

[His Dudeness]

could be a dodgy earth. have a look at the ignition connector. pull it apart and check for buring. it's under the tank where they all come together

[Timbollew]

I had this problem, eventually the thing stopped working completely. It turned out to be the speedo sensor, the pickup not the drive dog. First though check your cables not rubbed through on your disc or anything and the earth as the dude said.

[HovBiker]

Cheers both,when next off work I'll spend a few hrs in the man lab to see what I can find.

[HovBiker]

Hi guys.been lazy hoping the jumping needle would go away but sods law it's now going ballistic jumping all over the place.it does settle but then bounces around ten to twenty mph on the clock whatever speed I'm doing.
Took the front fairing off to get at the plug at the back of the speedo and lifted the tank to get at the connector box.faced with a shit load of wires and no clue what I'm doing.
Any chance of someone giving me an idiot's guide of what and how to check things.pics would be great if anyone got any .I've got a multimeter off a friend but like I said ,no clue what to check.
Cheers.

[Albert Herring]

Can't help with the electrical bit, but if you've had the front brake caliper off, check the sensor cable for damage first - there is an easy to make* error when refitting the caliper that leaves the cable liable to foul the brake disk, which produces the berserk needle thing on the speedo; however, the correlation with the indicators suggests it's probably the electrics.

*I found it easy, but I'm a bit of a mechanical numpty.

[HovBiker]

Cheers for the reply.I haven't had the front wheel or caliper off.
Will try and source a new sensor as that seems easiest job,hopefully that will sort it.don't know how easy they are to source or how much tho.

[HovBiker]

Just found a forum from back in March started by timbollew. His problem sounds exactly the same as mine and he sorted it with speedo sensor change.anyone out there got a spare one they want to sell?

[Albert Herring]

I'm in front of you in the same queue...

[His Dudeness]

Did you check the connector coming off the ignition?

[Burgess118]

check the choke is fully off!

[Timbollew]

Yeah it was the sensor knackered for me. Under the tank you'll see a white connector with three wires white red and black is my memory serves me. Best way I can describe it is triangular with rounded edges. Or you can just trace the wire back from the left side (sitting on bike) of the front wheel. It runs along side the brake hose. Check this cable for wear as they do wear through, but may well be the sensor. Mine stopped working completley eventually.

[HovBiker]

Apologies for dragging out this thread.have tried to source a speedo sensor and new they're £130 and rare as rocking horse shit second hand.
Took off the sensor and found it have been repaired in past but soldered joints seem all ok.
Don't want to spend my cash to find its not the sensor.
This is what speedo is currently doing when bike static and idling.
Speedo sensor unplugged...nothing.
Plugged in with lights off,speedo jumps around when indicator pressed.horn pressed nothing.passing light nothing.
Low lights on.jumps around when indicator pressed.horn pressed jumps around clock.
Dipped same as low but bounces as bike idles.
Full beam, does bounce when idles..bounces when indicator on..nothing when horn pressed...


Anyone make sense of that?
 Should I still change sensor or does it all point to earth problem on lights(where?)
Should I give up and use a Sat nav for speedo.
Apologies again for this novella of a post but this is driving me nuts!!!

[HovBiker]

I've also checked the ignition connector plugs and they seem ok.