Intermittent lights

[jonoy]

Any pointers

I have brake light and horn
But main lights and rear light are hit and miss whether they work of not.
I've seen that there is a earth mod that can be done under the headset. Could this solve the problem.

[rossclark]

You should usually have an earth in the headset which connects to the lamp rim and one to the bulb holder. These are connected to one of the screws which hold the gear rod down.

[JETEX]

Check if your speedo bulb holder is the type with a small screw in the bottom with a hole for the wire. If it is, change it as these are too long and can short out, resulting in no lights. ( I speak from experience ! ).

[jonoy]

My lights have now died only brake light now
I've looked at light electrics all look ok
Got a multi metre today
Not really electrical minded can I have some starters please

[Meds]

To help you fault find we need to know what system you are using and what model.
Is it standard or electronic, Spanish/italian/Indian
Do you have a kill switch or an ignition switch?

Your brake light and horn should be wired so that they will work whenever there is power available.

i would be looking at the electrical feed connections and switches in the lighting circuit.
clean and check all connections looking for broken, damaged or touching wires, particularly in the headset

[jonoy]

Brake light and horn work
It's Italian GP 12 v bgm Ducati 3 pin regulator conversion
Ignition switch
No cut out switch
Have been causing me intermittent problems for sometime
But now completely packed up

[CHRIS in MARGATE]

Take out the brown wire that comes from the main loom and connects to the regulator. May also be connected with a purple wire. Attach the positive clip of a battery charger through a 10 amp fuse in a fuse holder (about £1.50) at Halfords or The Range. Connect the negative wire of the battery charger to a good earth.
This is your live feed to the headset without the engine running.

Put the black lead of your new multimeter to a good earth and then measure on a range close to about 20 volts Volts AC and satisfy yourself with regard to the voltage at the back end of the scooter on your connected positive lead.
Now look for this voltage at the headlamp connector and work back.
Make sure the headlamp bulb connector assembly has a good earth.
I wish I was there because I could do this for you in no time.

[jonoy]

I do too. iam not good with electrics I've put up with it for more than a year now
and want to get to the bottom of it
Had to get bus to work Wednesday as it was still dark when I started
I've got the headset earth wired as per stickys manual
Iam going to get some new bullet connectors ,which size ?

[Meds]

If your brake light and horn work then your stator and regulator seem OK.
Take photos of the connectors in the headset to remind you where the wires came from so you can put out back as was.
It's likely the fault is in the feed to the lights within the headset.
This is a quick and dirty to prove your handlebar light switch and back light circuits by bypassing the ignition switch ( based on LI special/GP wiring sticky book page 267)
Remove the brown wire feeding the ignition switch and replace it with the orange that feeds your handlebar switch. You should now have horn/brake light/headlight.
Try a similar thing to prove the rear light circuit by connecting the black wire that goes into the loom into the space where the ignition switch brown should fit. You should now have horn/ brake light/backlight.
If these work ok then it's possible the ignition switch is at fault.
If it's the ignition switch you can bypass it completely

[Captain Pugwash]

Simplified loom fitted or is it a standard loom ?

[jonoy]

Thanks I will try that tomorrow
Does anyone know what size the brass connectors are

[Meds]

Can't remember sorry

[jonoy]

Simplified loom fitted or is it a standard loom ?

It's standard loom

[CHRIS in MARGATE]

Buy the red insulated bullet connectors. If you have one then solder them after crimping.

[jonoy]

Buy the red insulated bullet connectors. If you have one then solder them after crimping.

Yes have a solder iron

[jonoy]

It's odd I bought a bulb kit from one of the well known dealers and the pilot bulb is not as long as the one already fitted
So does not reach across connectors

[Captain Pugwash]

Listen to the advice that's being given because it all sounds good.

The reason I asked about the loom was because you had a brake light and horn, and a common fault on a standard loom when you fit a 12v DC system is the old junction box at the rear of the frame.

If your using a junction box....
Sometimes there's a poor connection to just one of the wires that feeds power up from the junction box so check each feed going in and coming out.

Your sounds like it's lost power on the brown wire to the headset that wire feeds the dip dazzle and back light through the switch gear and or ignition block.

So I would take a look there as well as the advice already given.


I often use a simple continuity tester available from most halfords and good motorfactors, easier to use than a multimeter some have a sounder and a light others just have a light.
The sounder/light confirms continuity, they usually have a switch that allows the voltage to be checked as well they're are super easy to use.

Good luck, Mark.

[jonoy]

It's a 12 v AC
Although the round junction box is still
In use if that makes sense

[Captain Pugwash]

It's a 12 v AC
Although the round junction box is still
In use if that makes sense

Check the round junction box connections and look for continuity between connections.

[jonoy]

there are 2 wires going into this