Electrical - k3 - headlight and rear light dim when indicators on.
 

Hi all,

I have an electrical problem with a k3. I have read numerous posts on this and other forums but don't know where to start.

When indicators flash both the headlights and rear lights dim intermittently, I.e indicate flash, lights dim, indicator off, lights back on.

I first thought it was just the rear light as I have read they can fail and the top LEDs are dimmer than the rest however if I unplug the rear light the headlights still are affected.

Everything I'm reading says earth problem but how do I fix this?

I've had no starting problems and it's done this for a while now, perhaps even since I owned the bike. It doesn't seem to be causing other problems but it will fail an mot.

Thanks.

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

Is that on idle or switched off? the lights will dim a little if the indicators are used as they are using power. Rev the bike to 2-3k and see if it does the same thing.

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

sorry could have given a bit more info there;

at idle the top 3 rows of leds on the rear light flash in time with the indicators from pretty much off to full - i suspect the light is at fault here as its a k3 and it seems like a common problem from what everyone else says, however, when i unplug the rear light unit the headlights still dim in time to the indicators and they do this at idle and with engine running and when revved to 3k and further. i only noticed the headlights doing it yesterday the bike was parked up facing a wall and noticed it in the reflection on the wall.

i unplugged the rear light and the rear indicators and the headlight stopped doing it however, i then tried a differnt indicator plugged into the rear to elimate the actually units themselves and the problem was still there so i dont think its the actualy rear indi's or light unit at fault. do all of the lights share a common earth? as other posts with similar issues always point to earthing problems.

thanks,

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

Mine does the exact same thing, has done for 4 years, when there is any revs on it won't do it however. its only logical really, if you add more things onto an electrical circuit the rest will dim down.

The issue should however disappear if its at 3K. there should be more than enough coming from the charging circuit to even it out. I am going to the garage to try mine. shall get back to you in a couple mins

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

Heres what mine does.

http://www.youtube.com/watch?v=YAHIV...ature=youtu.be

No problems in 4 years /31k miles. I wouldn't worry. Mate had a K3 that did the same

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

what voltage are you getting at the battery terminals with the engine running at idle, then same at say 3000 revs or so?

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

I don't have a multimeter at home and Im off work as I was knocked off the bike recently, hence the need to mot it to put it back on the road!!

Will a cheapo ten quid one from diy shop be alright? I could go and grab one tomorrow as ive been meaning to get one at home for ages anyway.

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

Yes it will IIRC mine was less than £5

As above, It's important to check the bike's charging, my bike does similar (not the same as that video though) - I started a thread but we never came to a conclusion. The battery charges and the bike works well so I'm happy.

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

just watched that video, that is exactly what mine does with ignition off then its abit more subtle with engine running but carries on even with the revs.

like i said i did just think the rear light unit had failed as theres so many posts saying the same thing on k3 and k4s and it seems to be cured with a light from a later model, but there must be something else going on as it is affecting the headlights even with the rear light disconnected. it did this at the rear when i last mot'd it and it still passed but techincally its a fail. im taking it to the same place so hopefully it wont matter but be nice if i could sort it before hand.

Re: Electrical - k3 - headlight and rear light dim when indicators on.
 

yeah thats the thing its done this for a while and always starts strongly so it must be charging. i havent ridden it for 3 weeks due to accident and ive been working on it fixing a few bits and its still starting everyday so im not overly concerned other than the mot.