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.

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

ok guys just nipped out to toolstation to grab a meter; 5quid inc. battery - bargain.

anyway;

igniton off - 12.19
ign on, not engine - 11.65
engine idle - 12.90
engine @ 3000rpm - 13.81

with the engine running it stays pretty stable past 3k upto about 7/8. should the ign off value be higher though? it started the bike again no probs. ive just pulled the battery and put it on charge as i have been tinkering with the bike all week and it hasnt had a run so it may just need a top up.

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

Disconnect the earth lead from the bike battery. Check the voltage across the terminals of the battery.

Then switch the test meter to show DC amps, connect one test probe to the bike battery negative terminal and the other to the bike wiring loom at disconnected negative connector you removed from the battery. With the ignition off you should be seeing something lower than 50 mA.

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

ive got the battery on charge at mo, i will try this in the morning -- what is this test for? sorry if thats a stupid question.

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

it's a current leakage test and can show up problems with your wiring or excessive current draw from alarm systems etc. Starting with freshly charged battery is a good idea.

Your figures earlier sound a little low to me, I would have expected a good 12.5 volts at the very least across the battery terminals. With ignition on, lights on, no engine running you would expect that to drop off to low 12v over 30 secs or so.

At idle I would be expecting around 13.5 - 14.5 volts at the battery terminal, perhaps rising up slightly when revved to 3000rpm.

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

Hi, I appreciate the help so far, ive got the results from today. I removed battery from charger first thing this morning and let it sit for a couple of hours.

So;

Battery: 12.89v
Ign: 12.30v gradually decreasing
Load test: 11.50v approx (battery whilst cranking)

lights on main beam:
Idle: 13.80v
3k: 14.4v
5K:14v

current leakage: 0.01mA (meter set at 20m on scale - i did this with probes both ways round as was unsure the meter was actually doing anything as the numbers didnt change at all, that means theres no leakage yeah?) --- there is no alarm system or heated grips on bike, it has had a few owners and up at 30k milage though so the wiring may have been played with at times.

Conclusions:

headlight still dims slightly in time with indicators; worse with hazards, but not as bad when revved up past 3k.
rear light is far more noticable so i suspect that the rear light unit is duff and this is probably a seperate problem. with a new rear light i expect it will dim only slightly as per the headlight. so.... is this slight dimming normal/acceptable? obviously there is slightly more power being pulled when the indicators/hazards are on but shouldnt the bike be capable of managing this?

finally, i was going to test the stator and r/r as per the tests ive found on other threads, but given these results i dont think i need to and my r/r has differnt wires than what i was expecting, perhaps its been changed before? There are 2-plugs, one has 3-black wires (so the 3-yellows that normally get mentioned?) and the other plug has 2 black/white and 2 black/red. 7 wires in total.

hope all makes sense.

thanks.

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

now those figures look a whole lot more healthy than previously. Charging circuit looks fine to me.

Keep an eye on the battery to make sure its retaining charge.

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

thanks thats what i thought.

any ideas on the lights dimming slightly though or am i just being paranoid and its not a big deal? lol

obviously the rear light would fail mot if they checked/noticed it as the top 3 rows are almost going from off to full in time with the indicators, but the headlight is just a slight ''pulsing'' really.

thanks again.

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

last time we saw this it turned out to be a faulty rear light unit (see http://forums.sv650.org/showthread.php?t=90593)

I'm pretty sure we had somebody open one up and figure out the reason, but I cant find the post.

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

found it - http://forums.sv650.org/showpost.php...5&postcount=97

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

thanks, i have read through that already, I think the rear light unit is probably duff as I have already said, but when I disconnect the rear light unit, the headlight still reacts to the indicators.

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

you read the second post on rear light resistor replacement?

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

yeah thats the one i meant actually,,, im not opening it up and replacing resistors ill just get a new unit off ebay im watching a couple now... Im aware the rear unit is probably duff,,,, but when it is UNPLUGGED the headlights still pulse?

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

:-), I wasnt suggesting that the front light pulse was related to the rear light cluster.

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

No probs, im Probably being over paranoid about the headlight anyway the rear is far worse. Just want to get it back on the road haven't ridden for about a month! Mot is next Thursday fingers crossed.

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

#Just don't replace the battery out of paranoia...potential waste of £60

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

I'll keep an eye an battery out all day tomorrow so I'll check to see if it still held full charge on Saturday.

Thanks for all the help guys I appreciate it.

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

Just to put abit of closure on this, I replaced the read light unit and that is working properly now in that the top 3 rows of LEDs are lit the same as the rest, although the headlight and rear light do pulse slightly with the indicators.

Charging system and battery still seem fine though.

Passed MOT this morning so finally back on the road!

Thanks guys.