Honda XR125 electrical problem

[Josh]

I got on my bike today and straight away realised the neutral light didn't come on. Shortly after i started my bike i realised my headlights and brake lights were also out so I headed home again and now also my starter button is completely unresponsive. My indicators still work fine so does the indicator light on my dash but the rest is completely out.. My bike started very easily with a bump start (obviously without even needing to touch the starter button).

Can anybody help me at all, what's gone on?

It's clearly relevant to note also that yesterday the last time I rode my bike was on a very bumpy surface so it was getting throw about a bit (speedbumps and extremely uneven mud/gravel) and also went through a few puddles so some electrics could of possibly got wet too.

Thanks a lot for any replies!

[Josh]

Turns out I have a blown fuse, I put the spare fuse in and it blew instantly after turning the key and the electrics coming on.

[Tango]

Yep....sounds like you've got a short circuit somewhere.....but without a wiring diagram I can't really help you too much....

[Josh]

So I should probably check all the connection for water/loose connections? I've got a multimeter but I wouldn't know at all what to do with it in this situation.

[rennie]

you'll need a handful of fuses!

You can check for continuity from one end

of a cable to the other, with the meter on the ohms setting,

(usually buzzes).

Also,on the same setting, you can check for anything that is connected

to earth that shouldn't be.

Also have a good look for damaged/burnt cables.

If it is only moisture a liberal spray with WD40 might help.

If all else fails disconnect things one at a time until it stops blowing fuses.

[acting_strange]

If the multimeter can be set to measurte AMPS then the two leads could be put across where the fuse should be to measure the amps drawn. Then each multiplug could be disconnected one at a time until it dropped to zero which would narrow down where the fault lies...

[Josh]

I don't really know where to start with the multimeter, all i've done so far is taken some wd-40 to it with no success and another blown fuse.

[rennie]

ok turn the dial to the right, almost to the bottom.

that looks like the buzzer function.

touch the 2 meter leads together it should buzz.

now seperate the leads put one lead on a cable and hold.

use the other lead to test various locations, if it buzzes

there's a connection.

[Joe4262]

if you aren't sure how to use the multimeter maybe a google? top hit is: http://www.ehow.com/how_7585821_use-dig ... 9205a.html and that's a basic overview.

you probably want to try the front and read lights first as they are one of the more exposed to water. Multi meter might not even be needed if there are any obviously wet/exposed/loose electricals?

[acting_strange]

ok turn the dial to the right, almost to the bottom.

that looks like the buzzer function.

touch the 2 meter leads together it should buzz.

now seperate the leads put one lead on a cable and hold.

use the other lead to test various locations, if it buzzes

there's a connection.

 

But all that is doing is checking continuity and if its blowing fuses like this its not a contimnuity problem...in fact it has too much "continuity"...usually a direct connection to an earth resulting in a high current flow and blown fuse...disconnecting all the connections and then connecting them up one by one is a better way of testing it...when it blows you have an idea of which colour wire you need to be checking for short..

[rennie]

so if he finds something connected to earth that shouldn't be

or 2 leads connected together that shouldn't be he's found the problem

There is no right or wrong way to fault find I'm trying to do the simplest.

[acting_strange]

so if he finds something connected to earth that shouldn't be

or 2 leads connected together that shouldn't be he's found the problem

There is no right or wrong way to fault find I'm trying to do the simplest.

 

Sorry mate....I wasn't saying you were wrong...I just dont think that is the way to go....but that is my MV experience speaking

[rennie]

I agree! If I was there, with the meter and my eyes,

nose etc. I would probably do things completely differently.

The OP says he doesn't know what he's doing so I'm trying

to make things as simple as possible.

I'm more used to thousands of volts and lots of Megawatts

nowadays but I did know about this stuff once

[Josh]

Thanks a lot for all of the helpful replies. Am I safe in saying it isn't the starter motor if the fuse blows before I press the starter button? The only things that come on are the dash lights and headlights automatically come on. So if I can find a way to disconnect the headlights then it might be able to narrow it down?

[acting_strange]

do your lights have an on/off switch?....some do some don't...if its blowing before you press the starter then we need to work out what circuits are being used at Ignition on...starting circuit obviously...I could do with a citcuit diagram....I'll see if I can find one...

[Josh]

Nope they don't have an on off, only a high beam/low beam.

Just in case these are helpful at all.

[Tango]

So it's the Head/Tail fuse that keeps blowing?

If that's the case remove both bulbs and try again......it's rare but not unheard of for a bulb to go short circuit......and if that don't do it you are then faced with checking all the lighting wiring to see if it's shorting down to the frame or to each other.....

[acting_strange]

Ive found the XL125 wiring diagram...

[acting_strange]

I also found this http://s574.photobucket.com/user/hmmmnz1/media/Honda/xr125color.jpg.html?sort=3&o=22

http://s574.photobucket.com/user/hmmmnz1/media/Honda/xr125color.jpg.html?sort=3&o=22

[Josh]

yes that's what is blowing, the 15a tail/headlight/horn fuse. I removed the whole front part (headlight section) and checked the wiring behind there and found something which could be causing a problem.

basically the big wire here (which I assume is the connection to headlights switch and whatever else)

it looks like the earth wire here has caused the plastic to melt around it (not sure if this is a problem)

[acting_strange]

yes that's what is blowing, the 15a tail/headlight/horn fuse. I removed the whole front part (headlight section) and checked the wiring behind there and found something which could be causing a problem.

 

Your piccy isnt clear enough....but if yoiu have melted wires than that will be at least part of your problem...you need to find out how much is burnt and where it goes...Isolate it... then repair/replace it...

[rennie]

I can't see properly either!

Is that sheath split or melted?

are there bare wires inside it?

seperate each individual wire and insulate them if you can

then see what happens

[Josh]

Haha yeah sorry I couldn't really get to it properly. I seem to of narrowed my problem down to being the low beam headlight, I found the bulb was blown and took it out - I flicked the headlights up to high beam and everything was fine, went down to low beam and as it has done before, lasted about 3 seconds then blew the fuse, however this can't be because of the bulb because I had already taken it out so simply replacing the bulb won't help, right?

[Tango]

If the fuse blew with the bulb removed then it can't be that.....if I'm reading your response properly.....so it would be in the dip beam circuit......so follow that through......

I did have a problem one time with a bike where the wiring or switch was shorting down to the bars......a bit of insulation tape around the bars where the switchgear located sorted this out.....

[acting_strange]

If the fuse blew with the bulb removed then it can't be that.....if I'm reading your response properly.....so it would be in the dip beam circuit......so follow that through......

I did have a problem one time with a bike where the wiring or switch was shorting down to the bars......a bit of insulation tape around the bars where the switchgear located sorted this out.....

 

And according to the circuit diagram the low beam wire is coloured white....