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Electrical arcing

Posted: Thu Oct 11, 2012 7:15 am
by jamjo
Hello all.
Wonder if anyone could shed some light on a problem we are having with wiring. We have changed the loom for a good quality one , changed the ignition switch to a casa one , new Ducati regulator . Have used a temporary power supply from the brown wire in loom to head set and earthed to frame to check lighting but I can see it arcing across the gear wheel to the frame and the lights only come on when I put pressure on the gear wheel and push it against the metal headset . Would anyone have any ideas as to why this would happen. We have earthed regulator to frame and back light to same screw also earthed to mag cowling bolt. I'm not very electrical so hope someone has some ideas I could try .
Thanks j

Re: Electrical arcing

Posted: Thu Oct 11, 2012 7:40 am
by mnpes
Have you Earthed the Headlamp Junction Unit :?:

Normally done via the Gear or Throttle Rod Olive Clamp Bolt

Use a Separate Brass Nut n Bolt myself ~ Terminations Crimped and Soldered ;)

Sometimes ~ On New Looms ~ When the Bullets or Ring Terminals are Crimped or just Squashed up

Only the Conductor Insulation is Crimped ~ Leaving the Actual Conductor Doing Nothing

This will then be a " Broken Circuit " ~ In Scooterists terms U/S

Re: Electrical arcing

Posted: Thu Oct 11, 2012 10:32 am
by coaster
I think mnpes has the truth of it there, the headset neets to be earthed as otherwise the only earth path is through the grease covered fork bearings and control cables. There should have been a wire from te ignition switch with both a loop tag and a bullet connector. As mnpes said, the tag needs to bolted to the headset usually, under the gear support bearing. The bullet connector goes into the junction block on the headlamp holder as well as the black wire comming up from the loom (that should also be connected to earth at the rear somewhere. Plenty of connectors to check for poor crimping. If you need new connectors, send Knowledge on here a PM, he does top quality crimp conectors and tools.

Re: Electrical arcing

Posted: Thu Oct 11, 2012 4:37 pm
by jamjo
Thanks for your replys . Out of the ignition there is a pink wire with a forked end I have put that to the headset bolt , then fed a separate earth from the bulb holder to under the throttle saddle . Is there any way to check for good earth . Oh also when I have the tempory power via a 12v battery and check for continuity ,if I touch the probe on the brown with one and any earth point around the scooter with the other it buzzes
Regards j
Ps will check all that has been suggested

Re: Electrical arcing

Posted: Thu Oct 11, 2012 5:06 pm
by coaster
jamjo wrote:Thanks for your replys . Out of the ignition there is a pink wire with a forked end I have put that to the headset bolt , then fed a separate earth from the bulb holder to under the throttle saddle . Is there any way to check for good earth . Oh also when I have the tempory power via a 12v battery and check for continuity ,if I touch the probe on the brown with one and any earth point around the scooter with the other it buzzes
Regards j
Ps will check all that has been suggested
That's narrowed it down a bit then, theimportantthingto bare in mind is that the earthing MUST be bonded back to the engine. There will be an earth wire wthin the loom that connects to the rear frame somewhere (rear junction box?) That must be a good connection andthe headset end ofthe wire must be in the same group of interconnected terminals in theheadset connctor block. Ifthe connction is brocken as in your car you will get arking and buzzing as it attempts to find earth trough gear cables and headset bearings.

Re: Electrical arcing

Posted: Thu Oct 11, 2012 5:07 pm
by Dimitrios_231
Electrical rule No1 for all the Lammies,
remove the paint at the point where the earth is going to be used

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If you use a Casa ignition,change the terminal of the pink from fork to a round connector.

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BEWARE on Casa ignitions you MUST join the purple together with the 2 other browns (one from the main loom the other from the ignition switch),otherwise you won't have pilot and rear light in the 1st scale.

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The following is not necessary,but I like doing.
On casa ignitions,there is a double brown.The long brown is used to supply the horn.
I usually cut it.This leaves a single brown.
I supply the horn,joining a long wire to the purple.

Re: Electrical arcing

Posted: Thu Oct 11, 2012 7:32 pm
by jamjo
Everybody thank you all for advice . Everyone was right ,it turned out to be faulty connections also not a good connection under the bolts onto the frame due to build up of paint hence the arcing through the cables up to the headset. The power of the forum solved this thanks again
Regards j :D

Re: Electrical arcing

Posted: Thu Oct 11, 2012 7:47 pm
by coaster
Happy days :fb: