headlight warning indicators

[Scottish888]

Can anyone tell me which of the three small indicators in the headlight shell are for and from left to right what is what.
There is also a larger hole in the top of the shell, what was that for.
Bike is a 250 mk3 1974

Regards,
Alex

[blethermaskite]

from the left .......blue,high beam indicator, middle....... green, side light telltale, right....... red, ignition on (and stays on all the time) the other two holes on a standard late mk3 headlight are to the left, lighting switch, to the right, ignition switch.
Cheers,
George

[themoudie]

Aye Alex,

See attached image of a 1975 Ducati 350 MKIII headlamp shell component detail.

From left to right the components are; light switch, warning light (ignition), warning light, green (parking light), warning light, red (main beam) and key ignition switch.

I note George's reply and suggest that it illustrates potential variables found on these bikes. My thoughts are to wire it the way it makes sense to you. Personally, I junked the 'rat's nest' of wiring, converted to 12v and simplified the whole loom, whilst incorporating some relays to improve reliability.

Detail taken from the wiring diagram for "450 Models: Mark 3, Mark 3 Desmo, SCR", pages 42-43, Clymer Publications, Ducati service, repair handbook, through 1974, 2nd printing June 1975.

If you require a copy of the wiring diagram, I can oblige and would send it to you as a pdf.

The 450 is running after a lot of kicking (6 hours)! Carb and ignition were both unknown quantities. At one point the backfire blew the carburettor clean off the inlet stub! Had to ditch the electronic ignition and replace it with a points system, then modify the carb. Sounds very crisp and sweet now, through the gutted Goldie pipe.

My regards, Bill

[Scottish888]

Thank you folks,
Much appreciated, I was concerned about the right hand indicator staying on but that must be the red ignition lamp (no colour left in it)
The headlight bowl I have is the same as you have shown Moudie but my unit has a 1 inch hole towards the rear at the top, it looks original but anything could have been done over the years, will grommet it.
From that hole I can see a fuse shape bulb that is always lit when the ignition is on, should that be the side light bulb?
@Moudie, great to hear you got that beautiful 450 fired up, it must have been some misfire to blow off a carb!, strange how the electronic ign did not help starting

Regards,

Alex

[themoudie]

Aye Alex,

"From that hole I can see a fuse shape bulb that is always lit when the ignition is on, should that be the side light bulb?"

In the wiring diagram that I referred to in my previous post on this thread, the festoon bulb within the headlamp is indeed the pilot light indicator bulb, as it is also the pilot light bulb. Please refer to my image of the rear of the headlight unit. The lower hole in the bulb holder is where the light for the pilot light shines through and at the same time illuminates the middle green warning light.

I also attach two further images showing the quality of wiring that might be expected to be found and the 'bodging' of fuses that at best could result in component failure and at worst cause a fire hazard!

As for the electronic ignition (EI) on my 450, I am not able to pass on any conclusions as to "Why?" it couldn't be adjusted to provide a spark at the correct time. The fact that we were juggling both ignition and carburettor variables, complicated the initial startup. Getting the points timed accurately was easier than the EI on a stationary engine and then enabled us to adjust the carburettor so that the engine would run. Once running, the carburettor fine tuning could then be achieved. I would suggest that EI is not a necessity to get a Ducati single running well, having spent ~6 hours kicking the engine over and experienced many kickbacks when using the EI, within a reasonable range of adjustment, I am not enamoured. I might at a later date give the EI another trial, but at present will "Keep it simple, stupid" (KISS)!

My regards, Bill

[Scottish888]

Thanks Bill,

All clear now. My one is also a mess of wires but there is room in there.
I never found a bike yet that had nice simple minimal wiring in the headlight bowl, all the manufacturers seem to be lazy and just cram all the junk they can into the shell..why not distribute some of the connections around. I will be doing this when re wiring.

Regards,

Alex