PX 125 lights dimming ?

[davy]

Hi all just  a quick one  had  a  problem  for  a few weeks now   my lights  dimm about  a mile into  a run seems  to  be  under load  but  they  return when i  park  up and leave it  ticking over ,i'm in the process or  sorting out what i  need to  rewire  it  but have checked all  earths  and  nearly  all  wires  individualy and re taped  them? even  changed  stator/regulator/flywheel/ cdi unit all  with  no  results (so  now  have  a couple  of  hundred  quids  worth  of  spares )wondered if  any  one  had any  idea as been looking at it  for  a while  and  starting to  over think it with  no results  so  any  pointers  would  be   good
cheers
davy

[kru251]

How old is your battery? Might just be losing capacity even though it appears to hold a charge, its discharge ability may be compromised.

[sbwnik]

What's the scooter? If it's a P range, then the battery doesn't go near the lights.

It's an odd one though. Are you sure it's not just your visor getting dirty?

[henri]

good 1 nic,next ya will tell him to eat more carrots. kru might be on right track tho,ive had a dead battery taking all the power ,giving nothing back an causing non-flashing indicators/slightly dimmer lights.davy ya need to say more detail,what scoot,battery/non battery,what headlight bulb ya got in ,sounds like somethings heating up under load an building a resistance ,hard to guess what by puter,ya could try taking it for a run an getting em dim an feeling for a hot component/wire/connecter.youve already swapped the normal culprits reg box n stator,an taken a wild un an done cdi an flywheel,most unlikely culprits .so i'm pretty stumped,try putting a new bulb in as they do have a lifetime an occasionaly survive the vibration/voltage peaks on a scoot long enough to reach its end.specially if its a modern upgrade halogen/tungsten bulb.it could be that simple but i'm guessing as cant think of anything else.if i'm right do i get a prize or just sworn at an a hammer thrown at me.either way when ya suss it please post the answer ,the answer might be keeping me awake at nights . H

[vespasco]

Get yourself a multi meter and with the engine warm check the voltage in/out of the regulator at idle and with revs.
If lights run off a battery do the same for the battery.
Work from there, then do the same with your loom until you find the culprit.
I would have suspected a bad coil but you've changed them all?!
You can also check you have it wired correctly.
Which model is it?

[sbwnik]

There is no way that a damaged battery can cause any of that.. I'd suggest conincidence.

I run my DC model P2 with no battery whatsoever, and it doesn't affect any of the lights: Quite simply, the whole of the lighting circuit is on the AC side, and unaffected by having a battery or not.

[davy]

i posted a reply on here yesterday where's it gone ?? dont want to repeat myself if only i cant see it ?

ok its  a vespa  px 125  2000,done all  the  checks  suggested but still  nowt even done an insulation test on alot of  stuff , my next  attempt is a new  ignition switch hoping its  just  breaking down and  not  getting the  12v back  to  regulator which it  needs to  work  properly
henri if i  tried   taking it for a run and  searching for  hot  spots  all  my  lights  would  have  come back on by the  time  i  started  looking  its  freaky
i  even tried  removing the  battery incase  the  plates  were breaking down and touching  but it  still  happened
davy

[bigd]

The lights on my PX dim when I put the indicator's on, I thought it might have been the battery but reading Niks posts here it must be something completely different. Confused!!

[vespasco]

May 13, 2014 21:16:28 GMT davy said:

........,my next  attempt is a new  ignition switch hoping its  just  breaking down and  not  getting the  12v back  to  regulator which it  needs to  work  properly
henri if i  tried   taking it for a run and  searching for  hot  spots  all  my  lights  would  have  come back on by the  time  i  started  looking  its  freaky
i  even tried  removing the  battery incase  the  plates  were breaking down and touching  but it  still  happened
davy

Try hooking up the multimeter to the regulator again (put it between ya legs and sit on it if you have to)! and taking it for a test run. (Warm engine/to replicate the problem)
if you can't replicate the problem when stationary at idle you can also try revving it!
If all coils and reg are changed and wired correctly then somethings getting warm/shorting/draining power somewhere surely?!
I take it the engine is still responsive/works, as usual?! Its just the electrics/lights right? Does the horn do the same thing? Do the rear lights and brake light do the same? I guess yours are all ac?

[glscoot]

i would check inside the headset and the connection box on engine, it sounds as if you have trapped a wire. i would also check all the bulbs are seated properly and a squirt of wd40 on all the electrical connections, switches ect. worst case scenario, continuity test on all the wires, probably need help with that, 3 hand job.
gary

[sbwnik]

The lights will dim when you put your indicators on, all the power is coming from the same AC output on the regulator, and it can't quite supply enough power to light everything at once. It's the only downside to the whole system. Change the rear lights to LEDs and the problem usually goes.

And yes, contrary to what anyone with any knowledge of electrics will tell you, you can run LEDs on an AC circuit. You shouldn't be able to, but you can. I assume it's because the current is changing polarity so rapidly, an awful lot more quickly than household 50hz, and the flicker inherent isn't noticable.

[vespasco]

May 14, 2014 16:56:55 GMT glscoot said:

i would check inside the headset and the connection box on engine, it sounds as if you have trapped a wire. i would also check all the bulbs are seated properly and a squirt of wd40 on all the electrical connections, switches ect. worst case scenario, continuity test on all the wires, probably need help with that, 3 hand job.
gary

Trapped wire was my first thought but apparently all connections and wires have already been tested wirh a multimeter including the headset switch he wants to replace!?
All other usual suspects (coils, reg etc) have also been changed
I still guess a short or incorrect wiring, if the above can be ruled out.

[davy]

I also think i may have missed something or am over complicating it and its something obvious so after my hols I'm going to rewire it all then i know for sure its not the wiring ?
I've re checked its all correct ? ? unless my diagram is wrong ?

[vespasco]

Do you have a way of checking it all with a known working stator, regulator etc? To rule those out.

Instead of replacing your whole loom it surely would be easier quicker and cheaper to thoroughly check you existing loom again.
You do actually have a multimeter dont you?
Whats the resistance on the coils?
What readings were you getting off the regulator?
Check your diagram is correct and check your connections are correct.
Im beginning to think you've over looked some of the above?

[davy]

Vespasco cheers ,i not only have a multi meter i also have an insulation tester RCD tester etc i'm a sparky :)i put in insulation test on all the wires and if you know what it means i put firstly 50v then 250 v /500v/1000v through the lot and none of the insulation was breaking down so i agree i must have missed something ,cant remember what the readings from coil and regulator actualy were but they were correct i do remember and i'm assuming the new stator/regulator/flywheel/cdi are in good working order ? i changed the CDI just because i had one:)it was all working fine until one day it stopped working or was working badly one problem i have is if i work on it on a night i have to put it all back together as its my daily ride to work,i dont mind rewiring it as i will be fun and i'll know its all correct and i can add a few bits for sat nav etc was even thinking of putting a volt meter and ameter on glove box just for the future :)also a clock as i'm sick of not knowing the time :)wife thinks i'm stupid but she married me:)

[sbwnik]

Davy... If I was you, I'd do that now. A loom is what, forty quid? I'm sure you could manage to make one yourself for a fiver, you'd be able to modify it from the start, and you'd know it would be right.

[davy]

That's my plan but will give the ignition switch a go first as it should arrive today .was also thinking of taking cables straight to switches and headstock instead of having plugs under horn cast what do you think ??

[davy]

Seconds thoughts it might not be such a good idea there's alot of cables doubled up under there ??

[henri]

yep,as a sparks i think you'd agree the less connecters the less to go bad ,there only there to make factory assembly easier ,an you cud of declared ya "sparky" qualifications wud of stopped us giving "beginners" tips an using baby-language .i make my own looms up using 7 core trailer wire an shrink-wrap off e bay ,an if you want to simplify it you can work from the electronic conversion wiring diagram on beedspeed website.using trailer wire means not all the colours match the piaggio colour coding but is a hell of a lot cheaper than buying rolls of right colour auto wire at 5-6 quid for 5 metres when ya only want 1 metre.just amend ya diagram in case ya forget or want to sell scoot on.
an yes nic leds do run on ac even tho designed for dc an the flicker isnt visible to the eye,unless its a really weak stator an low tickover .an on earlyier vespa's its the horn instead of the indicators that dims the lights for the same reason .my mot guy always tries to get me to do lights/brake light an horn at same time ,it gives him a laugh if he can get scoot to die ,that an it lowers the tone of the horn from a ridiculous noise like a duck crapping through a sewn up a***ole,makes him laugh too much to sign the mot.
an no i have never sussed why the led tail/brake light i tried to put on mates lamb-chop worked as a kill-switch no matter how i tried to wire it,have refused to try anymore.but the led's that i put in his px for warning lights work ok with a resister in series to keep voltage down near the nominal 12volt there made for,before they'd blow in use at anything more than tickover . H

[sbwnik]

That's bizarre on the tail lights, if they were higher ampage then I could just about understand it.. Very strange.

I'd stick with some sort of plug in wiring under the horn (or wherever) just to make things like dropping the forks easier.

[vespasco]

Ah! So youre a sparky!! so sod it, re wire is easy!!
Yeh, defo, add extra wires, future proof it, mod' it up.
I made my own loom, (added extra wires too) and i know very little about electricity. No issues at all , peace of mind knowing its gonna last too. So far do good!

If youre lucky the new switch may solve it as it could be a dodgy wire in that part of the headset, which is why its ok at idle? Like, your throttle /cable could be the cause? Moving/shorting out a wire somewhere (I dont recall you saying if it revs ok/lights work ok at revs when stationary)

[davy]

lights work  fine  at  tick over and  when  revved  its only  on load  i  lose  /or nearly lose  everything  there all  there  just  very very  dimm. i  took  the  old ignition switch  off and  changed it  and the red  wire was barely attached maybe by 6 threads even though  it  seemed ok when tested ?will  try it out tomorrow with  new switch,but still  may  rewire any way ?? as you  say  future proof it

[davy]

ok loosing the will to live now switch didnt make a sh*t of difference though i suspected as much ? so gonna start re checking all connections as cant get any cable to start rewiring it till next week and i'll probably leave it till after the hols to start,thanks for the help so far it will be something basic and obvious that i've completely over looked i bet

[henri]

yep on ya last post,i think it cud well turn out as a DOH!! moment,we all get em,an being a qualified sparks/experienced mech-head can make ya more prone too em,well it does for me anyway,thinking i know it backwards/all an scoots/bikes/cars ,bless em, teaching me a lesson .walk away for a bit ,do sumting else with ya hols,an when ya head clears come back an start from begining/first principles.an i bet when ya suss it you'll want to kick yaself in the jacksy,dont tho as it wrecks ya knee joint an makes kickstartin the vesp painful,i know,ive done it myself too many times .nowadays when its needed i go to blackpool an tickle a stroppy donkey ,works every time an the guy dont even charge me for it . H

[davy]

Blackpool's fecking expensive for a family of four :)while getting the ignition switch i also got a light switch without the wires thinking i'll just attach the wires with terminals instead of solder so un-soldered the old one went to put the new one on and it has no off position on lights and the horn button is N/C ?? so the way my horns wired its on all the time so as i didn't want to start the rewire just yet (and i have no cable )had to re solder the old one back on :)also turned the tick over up quite a bit and waited and after a while the fault occured(lights dimmed)so checked the volts from stator and ok 31v,starting to think its may not be wiring the amount of times i've looked at it so might put all the new bits of kit back on cos i can and give it another run out tomorrow as i have feck all better to do with my time

[davy]

Quick update after hols ,before buying cable to rewire decided to go back to my original diagnosis of regulator and bought a genuine spare from different supplier after two from original supplier and hey presto all ok ?? feckiing regulators dont want to name original supplier if i havn't already but there going to refund me for all parts purchased in the location of fault (which i think is nice )so sending back two regulators a flywheel a cdi unit and a stator,and bike now ok so thanks all for input
davy

[henri]

2 in a row bad out the box ,bet ya wish ya hadnt bought a lottery ticket that week, with luck like that theres no way would ya win anything, he must have a bad batch ,or dodgy supplyier , you get the odd 1 ,cdi's,regs,spark plugs even bulbs that come bad ,but 2 in a row ,bet he didnt offer comp for the bald spot from tearin ya hair out tho, scoots ya got to love em,eh , henri