Duke 390 Speedometer intermittently showing zero when riding. 

Led bulb voltage and wt let me know bro

Yep still got it. Send me an email to Don.knight@bigpond.com With your address and I'll send it your way.

Mine stopped working when you press it longer than 3 sec.. what could be the issue

Same circuit at the original bulb. Plug and play.

Interesting enough, after the bike sits for a few weeks (winter here) the speedo has a few hiccups until the battery fully recharges then it's fine. I'm wondering if there not a voltage regulator in the speedo circuitry that's on the way out. Time will tell.

@@mostlymotorcycles. Yep - it does definitely seem to be related to the charging circuit in some way. I've ordered one of the headlamp globes you recommended and I'll put that in and see how it goes, but to be honest I suspect my stator is on the way out, but if the lower power globe helps extend it's life then thats good for now. My speedo started playing up a few months ago literally after I'd over filled the pertrol tank and fuel spilled out over the bike. Once I started riding from the petrol station the speedo started playing up (my thoughts at the time was that the fuel had gotten in to some electrical connectors and dried them out/increased resistance so I blasted a few with WD40). Of course it could simply be coincidence that the fault appeared at that time. It's been intermittent since, and I recently come back to Sydney after 3 months overseas (and the bike actualy started on the third attempt without doing anything which impressed me) - so I fully recharged the battery overnight, tightened up the battery connectors and the speedo worked fine - until my next ride when it started reading zero again. So with a fully charged battery it works (my battery is only about 1 year old) My bike is 10 years old (only 15,000 KM) but there are so many annoying faults occuring, like the dodgy clucth switch which makes it stall for no reason - it fails when you stop at traffic lights or a junction) and my fuel pump went and started leaking fuel - that integrated unit alone was $650 and with mechanics labour it was expensive.... The new 399cc Duke looks interesting though and I'd like to try the new 400cc Triumph when it lands here (be a few years before I can afford a 2nd hand one of either though I'm sure) Anyway, thanks for your help - love your work with the oscilloscopes etc , and I'll let you know how I go. Cheers, Neil

Keep me updated for sure.

If it started after you washed it, id go with cleaning the connector. If no change, try just disconnecting the headlight to see if it helps.

@@mostlymotorcycles. Thanks for replying! This afternoon I will also call a ktm dealer to ask if they have experience with this problem, otherwise I will try cleaning the connectors

My ktm Duke 390 bs3 in speed is not showing some times it shows but always it is showing zero ...I have checked in ktm service centre and local gurage also ..I have chenaged speedo meeter wire also what to do sir any solution from ur side

By the way, did you also try with a cheap led ligh bulb?

Tried taking the bike for a ride without the headlight, and no speedo issues. Ordered a led headlight and position light.👍 Weird though, looking in the manual, my battery is charging quite a bit higher than the lower limit..

Very interesting. keep me posted on how you go with the led.

Seems the stator in the early Dukes is a little week. I've heard of quite a few failing. If the accessories are things like seat of hand grip warmers those do pull extra amps, could cause an early stator failure.

@@mostlymotorcycles. thanks man, i'll consider changing my battery to a higher amp hour, see how it goes if it solves my speedo going zero. im currently using a 12v 6 amp.

Sounds like a different issue to mine. Your right It's not a permanent fix if the stator is failing, but fitting a low wattage bulb may make it hang in there a little longer. Check a previous comment from a dude who traced his issue down to a faulty contact in his ignition switch. This was causing an intermittent low voltage to the speedo cluster.

Thanks. Most Interesting.

How about a switch to turn the light off during daytime. That would not be legal in Australia though.

@@mostlymotorcycles. That is illegal in my country too, today i tested led bulb on a private road to see if that will really help and i didn't get any 0 during the ride

12 volt. 15 watt led would be fine.

I am facing same problem, did you find solutions

Try charging the battery over night if u can. If speedo issue improves or goes away theres probably a charging circuit issue.

​@@mostlymotorcycles. hi, thanks for the advice, I tried but still the same problem, I did the same test as you by putting the multimeter on the handlebars and doing the test with/without the headlight, it's not clear if it improves or not. in my case there are moments in which it seems to mark for about ten seconds and then goes away. but the voltage in any case it is always of 13.5/14 V when I am on the motorbike and the problem occurs the same, I put the multimeter cables on two power cables under lock and key in front of the motorbike as you did (I don't know if they are the same but I think yes), do you recommend trying to change the phonic wheel? Already changed only the elettronic abs sensor near. Is it possible that the phonic wheel doesn't transmit properly the frequency?

It's unlikely to be the problem as it's just a metal plate. Check the gap from the pick-up to the disk. As the voltage is good I'm wondering if it's a fault in the gauge cluster itself. Only way to know for sure would be to swap it out with a spare from a friends bike or something like that. Otherwise I'm out of Ideas. Worst-case would be if you bought a new instrument cluster and the fault continued.

@@mostlymotorcycles. Hi I have an update! First of all, thank you so much for your reply, you're really kind! I dismantled the fuse box at the back seat and found the 30a main fuse loose, but it still works. so I decided to change all the fuses and clean all the contacts, now the problem seems to have been solved, at this point I think I should do a more thorough cleaning of all the contacts. the strange thing is that I had the new speed sensor mounted and as soon as I tested it on the road it seemed to do it (1-2 times) then it seemed to have stopped completely, I refitted my old sensor and now it really rarely does it, I don't know whether it can also center the sensor as well as the contacts! one thing is for sure, the problem has reduced exponentially since I changed and cleaned the fuse contacts

Most excellent.

Sounds like a different issue. Maybe a broken or misaligned picup. Or a corroded connector.

What do you mean by pickup here?

And could you even suggest which all connectors need to be check for corrosion?

Speedo dropping to zero is low voltage related. Could be the generator or battery failing. Try full charging the battery and see if the problem stop for a while.

Thank you for answer! Today I puted battery to charger, so tomorrow I will see. But now I found some strange thing.. When I ride on motorcycle with switched off motor the speedo shows speed normally. When I ride with switched on motor the speedo dropping to zero. 🤷‍♂️🤷‍♂️ So I think abs sensor is OK and speedometer too, but problem can be somewhere in electroinstallation and it can be hard to find it. 🙈

Hello! The third secret button is turning on/off abs. Two ground wires and two power wires fit to the dashboard. Probably, there was a bad contact in some connector, so 7 or less volts reached the dashboard. The stator of the generator is in perfect order. After all, at the beginning during the test run there were no reports of low battery voltage?! And the lamp didn't go out. Cleaning the green and black connector next to the dashboard helped me.

Thanks for the info.