headlight fault .. again... arrrrrgh!!

[Janx101]

yeah .. its back ... the low beam keeps on switching itself on and off... the highbeam works all the time though ... so i know theres gotta be a busted wire/bad plug connection/bad solder joint in the lowbeam side .. somewhere!! .. i start looking with the tank off etc .. with the multimeter (yes addy i went straight for a multimeter!!) .. testing for volts AND resistance along the way .. pulled apart the left and right handlebar switches so i could test for resistances along that route too .. i AM going to FIND or REPLACE this motherf......r!! .. 

my issue is .. its real easy to find a fault (eventually) when its there .. cos this is intermittent ... as i push the probes around in the plugs and wires and connectors etc .. something moves .. and the bastard works!! .. then i have to wiggle crap around till it doesn't .. then try to isolate the issue again... several times i have 'found' a low voltage 'in between' the left switch and the big yellow plug under the tank .. soon as i shift spots to try isolate it further ... there we go!!... its good again... 

i'm referring to the haynes wiring diag all the way and i know roughly where it HAS to be .. but i'm sick of it... i might just order another whole front end harness including switches and be done with the hassle!!! ..

another minor thing... when i pulled the left switch apart .. i was slightly annoyed... a little black thing fell out .. about same size a LEGO single dot square unit ... got a slanted 'top' to it .. i can see wear lines on the thing so i know its usually against something in the switch that moves ... but for the life of me i cant visualise where the little bastard came from!! ..

its getting GAMMA RADIATION over here folks!!  --- > 

[Janx101]

another minor thing... when i pulled the left switch apart .. i was slightly annoyed... a little black thing fell out .. about same size a LEGO single dot square unit ... got a slanted 'top' to it .. i can see wear lines on the thing so i know its usually against something in the switch that moves ... but for the life of me i cant visualise where the little bastard came from!! ..

found this one at least .. little tension slide block for the choke....

but on the main problem.... the lowbeam has been lit up like a champion despite all my wigglings of wires... i know how its gonna go though... i will put everything back together and 'woops there it goes' ... if its a wiring thing then i will just replace the harness .. just cant go through unwrapping all the wires .. finding the prob and making a 'bodge' fix... wrapping again and finding another fault happens later....

this is the second wiring issue .. i bridged the right side switch harness plug a while back and then replaced the plug with another more recently... yes yes i know it may be just my handiwork... i'm fairly sure i made good connections though...

i'd rather replace the harness with a brand spanking new one (if i can get one) .. that way i know its all 'approved' and not a mess of bridges and patches ... 

as predicted ... soon as i bolted the tank back on... started it up .. and the engine warmed up... zip .. low beam out... sigh ..

i'm gonna stop pretending i know how to find the bloody problem... buy a harness brand new... take it to a local trusted mechanic/auto electrician .. and say ... "put that in there please, and send me a bill" ... i just cant be f....g bothered

in the meantime i've adjusted the high beam several winds down on the adjuster so its half high/half low .. and left it at that ...

when all the suspension bits come .. he can do that too.... i dont have the patience for this crap!

[iclrag]

Electrical tape... LOTS of electrical tape.
but seriously, if you know the area and dont want to replace the harness, do a thin layer of you favorite color and wait, when the tape wears through and the problem comes back un-wind it and look for the hole, then you'll know where the problem is

[Janx101]

after a short ride yesterday i noticed...... when the bike is sitting still and the heat builds up under the tank and heats the wires .. the headlight goes out.... when i start moving again and there is airflow (a bit) under there ... the light comes back on...

well i think its a fragged wire inside its sheath .. heat is affecting it...

also my high beam telltale bulb is not working...

still dont care ... i'm gonna re-harness the biatch when i have the $$ ... i have already fixed light and or wiring issues in 3 separate areas .. and even my bodge fixes annoy me...

new harness .. and if i can work out how i'm gonna put some form if insulation/lagging around the wires that run near the engine...

i can fix lotsa different things.... i have faith in my fixing credo .... but i also know when to leave it and get a pro to do it .... so my 'inner psycho' doesnt come charging out and trash the suburb!! 

[Funderb]

Well, problem solved. The solution is: don't stop moving ever. 

[Worm]

Well if the high beam is always working correctly, it has to be in the wire from the switch to the headlight for the low beam. I would check the connector that this wire runs through. Push the two wires into the connector that are for the low beam, the little prongs inside may be a little loose and when the connector heats up and expands a little, it loses contact. My reasoning is that the only thing thats different between the high beam and low are the contacts in the switch and the wire running from the switch to the headlight. Power coming into the switch is the same and ground is the same so the high beam working eliminates any issues with those. If you have to, replace that one wire.

[Janx101]

yeah thats what i thought too Worm.... but the multimeter reports that section ALWAYS has consistant resistance and volts ... the fluctuation comes in somewhere after the other side of that plug into the harness ...

the orig owner stacked the bike and made a crap attempt (including moving wires into pinch points) at repairing the bike.. the 2nd owner was pretty good but i have found other 'fix it .. NOT' issues around the bike... again incl wiring... and now with my few repairs to harness .. it looks kinda messy ...

i dont mind replacing the harness ... but if i go into the wiring again and try to find the 'one little break' ... i may just go postal!

thanks for the thinking on the issue though .. confirms my reasoning.... just not the location as i thought it must be too!! 

[adidasguy]

Headlight - simple to trace down.

1. You got high - so power to switch is OK
   a) then could be low bean contact on switch or wire
   b) could be connector from switch unit into the wiring harness - either end of that connector
2. If high works, then you also have good ground on headlight so
   a) could be flaky low beam so swap headlamps
   b) could be flaky connector to low beam pin

Flaky connectors:
   a) could be corrosion
   b) could be loose fitting as they do open up
   c) could be poorly crimped wire at the connector pin or wire breaking off at the crimp
   d) pin could be pulling out of one part of the connector

If still stumped, run a direct wire from the low beam wire from the control to the low bean pin on the headlamp.