Systems to Brighten Dim Lights on Alt.Powered models

[DewCatTea-Bob]

" I think it makes sense to be able to start and run the bike with the lights off and only turn them on as I get underway, and this should be easily handled by a 3-way ignition/light switch. "

____ Let me know when you choose a key-switch that suits, and I'll then help you figure how it should be wired-up.


" My outstanding questions at this point are how to wire in the battery, which may or may not answer the question of where to route the white and yellow stator wires. "

____ The pos.post of the battery should go directly to your key-switch!
__ The WHITE-wirelead (from the alt.stator) shall be left unused, (at least at this point), in this case,, due to YOUR choice of options.


" Also, the OEM specs called for a 6 volt, 7 Ah battery. Is this still the appropriate choice? "

____ If you were still stuck with the original battery-tray, then that stock-sized battery would be your best choice! _ But I'd suggest that you just get whatever 6-volt battery you can find cheapest, that you can also find a way to support it.


" can I wire the Sebring headlight switch to serve as the 3-way switch? "

____ The Sebring headlight-switch is indeed capable of doing a lot of connections but, it can't do everything which ought to be done. _ We will however get it to do the main connections which your choice of options require!


" Looking at the early SCR/Mark 3 diagram, however, I cannot determine how one kills the motor. How did one kill the motor on these models? "

____ Well first you try to remember to shut-off the fuel-petcock a couple blocks before you reach your destination, then park on it's side-stand, and then it dies! , Or you just dump the clutch, with brakes on.


____ Your premature wiring-diagram indicates an ignition set-up powered by battery-power, BUT your Scrambler does not include the correct parts for that.
The YELLOW-wirelead from the stator is to go directly to the ign.coil & connect to the same terminal as the ign.points.
__ Try another attempt at a diagram which will reflect these added details.


Tillater,
-Bob

[kmev]

Your premature wiring-diagram indicates an ignition set-up powered by battery-power, BUT your Scrambler does not include the correct parts for that.
The YELLOW-wirelead from the stator is to go directly to the ign.coil & connect to the same terminal as the ign.points.
__ Try another attempt at a diagram which will reflect these added details

Bob, you're killing me here!

But I love ya! Let me take another shot at it - I'll get back to you!

Keith

[DewCatTea-Bob]

" Bob, you're killing me here! "

____ I don't really get why you say that!?


" First, as I received the bike, the yellow wire was connected to the coil. "

____ Okay, that was correctly wired then...
I had thought that since your lighting-coil was so dark, that perhaps it had been (mistakenly) wired to the points & ign.coil, and thus that power-coil got cooked & burnt dark.
As a lot of people don't realize which is the correct stator-wire to connect for the ignition, and so use the wrong wire!


" I do have all the different wiring diagrams from the service manual to reference. "

____ Well, after you're done,, your new wiring-system won't be much like any of those stock systems. _ (But it will be better than most!)


Fun-Cheers,
-Bob

[Desmoto-M.3]

I just got back home tonight and i get on my PC to catch up on email, and then decide to come here to my new favorite site to take a quick look at how things are going, and i find this very interesting new thread!

Bob, my narrowcase Mark 3 also has it's headlight too dim whenever not running at higher rpms!
From what I've read before, I should have the "40 watt" alternator, right?
Can you tell me if there is any way to improve the brightness of my headlight for when I'm riding normally at medium-low revs, hopefully without having to modify the alternator?
I'm willing to add a battery because i want to add a horn anyhow too. So can a battery be connected some way and also be kept charged any way at all, like the 28 watt setup does?

One other thing I've noticed and bothers me, is that when the brake light is activated, the tail light actually gets dimmer for at least a second, before the brake light gradually makes the tail light get any brighter than it was when just the tail light bulb was lit! The transition seems so slow that you can't really tell for sure when the brake light has fully lit up. And once it's had time to finally get turned on as bright as it goes, the only way to be really sure that the brake light was even really on, is when you see it go off !
Is that normal too? Or is that strangeness caused by some kind of short somewhere?

Thanks for any advice!
Ken

[DewCatTea-Bob]

" I should have the "40 watt" alternator, right? "

____ Right, the narrow-case Mark-3 has the more common "40-watt" alt.stator, (same as the pre-1966 Scramblers have)! _ (And I have far more experience with this model of stator, so I'm familiar with it enough to more clearly picture it in my mind!)


" Can you tell me if there is any way to improve the brightness of my headlight for when I'm riding normally at medium-low revs, hopefully without having to modify the alternator? "

____ I've had just as much success with solving the dim-lighting issue on these 40-watt models (as with the 28-watt models)! ... Unfortunately, the only way I ever knew of, is to modify the alt.stator.


" So can a battery be connected some way and also be kept charged any way at all, like the 28 watt setup does? "

____ Yes! But not like the 28-watt set-up originally did.


" when the brake light is activated, the tail light actually gets dimmer for at least a second, before the brake light gradually makes the tail light get any brighter than it was when just the tail light bulb was lit! The transition seems so slow that you can't really tell for sure when the brake light has fully lit up. And once it's had time to finally get turned on as bright as it goes, the only way to be really sure that the brake light was even really on, is when you see it go off !
Is that normal too? Or is that strangeness caused by some kind of short somewhere? "

____ I'm very quite familiar with that very poor brake-light situation on the narrow-case Mark-3 & pre1966-SCR models!! _ Is there any owner of one of these models who is not aware of the 'slow-glow' brake-light issue?
As every one of those models I've ever owned, did exactly the same just as you've described it, (whenever the engine-revs were not high enough).
One thing that can help-out a bit, is to run a wire directly from the tail-light shell to the grounding-point where the ign.coil mounts.
__ The main way to completely solve the 'slowglow-brakelight' issue, is to install a battery and replace the grounding-type 'opening-circuit brakelight-switch' with a normal-type 'closing-circuit brakelight-switch' .
I have much more related info on this 40watt-system mods but, I think it all ought to be posted under a separate new thread, so as to avoid any confusion since it's kind-of easy to get things confused between the very similar but quite different 28watt & 40watt systems.
So I'll post a new related thread when I get a chance to write most of the related details.


GoodCheers,
DCT-Bob

[kmev]

Try another attempt at a diagram which will reflect these added details.

OK, here's my latest attempt with your input, Bob, but I'm still uncertain about a few things. I"m assuming the switch will connect the rectifier, battery, and ignition in the ON position, and the lights will be turned on in the 3rd position.

Will this configuration kill the engine when the key is turned to OFF (i.e. will the spinning alternator still allow the coil to fire even if there is no power coming from the switch)?

This also begs the question, when and how would I ever use the white wire?

Thanks again,
Keith

[DewCatTea-Bob]

" I"m assuming the switch will connect the rectifier, battery, and ignition in the ON position, and the lights will be turned on in the 3rd position. "

____ No, it's not going to be possible for all of that! - (Unless you come-up with a fantastic switch which can possibly handle everything that it would need to do! - [And such switches do indeed exist, as I've had to wire them up, in the past!])
You can use the Sebring-headshell/bucket's switch to connect the battery-power & the rectified-power and make those combined power-outputs available to the DC-loads (of the system which require battery-juice), only! _ That connection will occur only when the key is inserted.
Then turning the key to it's "2" position, will turn-on the lights.


" Will this configuration kill the engine when the key is turned to OFF (i.e. will the spinning alternator still allow the coil to fire even if there is no power coming from the switch)? "

____ This question would make understandable sense if the Scrambler-type 'GREEN-labled ign.coil' required any power/juice from the battery, (in-the-first-place)...
While your somewhat updated wiring-diagram is neater-looking, it STILL indicates that the ign.coil is connected to the same power-switch as the battery is! _ So next try, be sure to remove that incorrect wire-connection! - (I don't wish to "kill" you again, so just erase it!?)
__ And where you show that incorrect wire-connection to the ign.coil, that 2nd ign.coil-terminal should be connected (with a relatively short wire) to the grounding-point where the ign.coil is mounted.
Also, with the stock 1966-Scrambler's electrical-system, a 3rd wire was also connected to the 1st-terminal on the ign.coil,, and that 3rd wire goes to a (non-Sebring type) ign.switch which shorts that 1st-ign.coil-terminal to ground -(in it's stock headlight-shell/bucket), to act as a kill-switch when it's key is removed.
We could do the same type of thing, using the "1" position of the Sebring-headshell's switch!
So at this point, it would be good for you to remove the fuse-carrying circuit-board from out of that headshell/bucket, and get yourself familiar with it! - (So we'll better know what I'll be trying to tell you, concerning it.)


" This also begs the question, when and how would I ever use the white wire? "

____ That's a question for the future, since you will not be running the motor at high RPMs for long periods with the lights turned-off. - (Thus no need for it [in your case].)


Tillater,
-Bob

[kmev]

Bob,

First of all, thank you for walking me through this. Ducatis are new to me and this bike came in a stripped, non-runable condition, so I probably have a lot of elementary questions. Your last post was especially helpful, as I didn't even realize the Aprilia switch made contacts just by inserting the key.

Hopefully this iteration of my schematic is correct. I also looked at the switch and attempted to determine what posts I should wire things to, and labeled the switch accordingly. Since my switch is a bit hacked to begin with, I also posted a pic of the switch to help show what my wiring plans are. If I have chosen correctly, the rectifier and battery will be connected when the key is inserted, the lights will come on when rotating the key counter-clockwise, and turning the key all the way clockwise will ground the coil and kill the motor.

On the schematic I didn't indicate what switch post I'll wire the coil's ground to, but it seems it would work if I wire the red wire to ground and the the coil to the snipped wire attached to the fuse mount (see image).

"Screw post" in my schematic refers to the post with the grey wire to the right of the red wire.

Does this seem reasonable?

The white wire - should I just remove it entirely from the stator or run it out of the engine case and terminate it near the battery for possible later use? I may install a dimmer switch and horn at a later date - would this involve the white wire? Also, it may be beneficial to comment on what the white wire would be used for, for the benefit of others viewing this thread that may make wiring choices different than mine.

Lastly is a pic of the Japanese coil that came on the bike. With only one wire (and a condensor?) I don't think this coil is usable with this wiring scheme. Can I simply go to NAPA and get a 6v auto coil?

Thanks again,
Keith

[DewCatTea-Bob]

" Hopefully this iteration of my schematic is correct. "

____ Yes, I've looked-over that latest wiring-diagram and everything is now completely correct (considering all the ELECTRICAL-connections, however the PHYSICAL-connections will have yet to be worked-out).


" If I have chosen correctly, the rectifier and battery will be connected when the key is inserted, the lights will come on when rotating the key counter-clockwise, and turning the key all the way clockwise will ground the coil and kill the motor. "

____ It seems that you've probably figured-out what I was intending to suggest, (after I'd come to realize that you had familiarized yourself with the circuit-board).


" On the schematic I didn't indicate what switch post I'll wire the coil's ground to, but it seems it would work if I wire the red wire to ground and the the coil to the snipped wire attached to the fuse mount (see image).
"Screw post" in my schematic refers to the post with the grey wire to the right of the red wire.
Does this seem reasonable? "

____ I'm just not sure... I'd really need to hold your circuit-board in hand & inspect, in order to become confident of whether or not what you're thinking is going to work okay.
I had and still expect to tell you what my plan was. _ And when I do, you'll then know if it's the same as that which you're thinking.


" The white wire - should I just remove it entirely from the stator or run it out of the engine case and terminate it near the battery for possible later use? "

____ I highly suggest that you go-ahead & add it to your new stator-cable (providing that it will fit okay, along with the other 3 wire-leads), as it may yet be of use some day.


" I may install a dimmer switch and horn at a later date - would this involve the white wire? "

____ No! ... (It seems that you somehow missed in my previous posts on what the WHITE-wirelead's purpose could be.)

" Also, it may be beneficial to comment on what the white wire would be used for, for the benefit of others viewing this thread that may make wiring choices different than mine. "

____ I agree but, I thought I had fairly-well covered that in previous postings? - I'll check through them sometime and see if I omitted anything of real importance (other than the physical-connections involved), concerning the use of that particular alt.coilwire-extension. _ (I know that I would never do a wiring-job for myself without making use of it!)


" Lastly is a pic of the Japanese coil that came on the bike. With only one wire (and a condensor?) I don't think this coil is usable with this wiring scheme. Can I simply go to NAPA and get a 6v auto coil? "

____ Well it's too bad that you don't have the stock 'Green-coil' but, that Jap-ign.coil is no doubt superior! _ Whether or not it's actually suitable, I'd have to see it disected to determine that.
__ The stock ign.coil is not actually a "6-volt" coil. _ The type of ign.coil you need was used on many Italian bikes which don't employ battery-powered ignition, like old Benelli mini-bikes. _ Also, many old out-board boat-motors use similar ign.coils.
If you can't find such, then just try a 12-volt automotive coil & see if it works.


____ Do you also have the factory wiring-diagram which shows all the wiring that's within a Monza/Sebring head-shell/bucket ? _ As that would be helpful to correctly understand the circuits of that circuit-board (which you have posted). _ And if you could also post a copy of that, it would help me to explain to you (& any others) what's going-on here.


JoyfulCheers,
-Bob

[kmev]

And if you could also post a copy of that stuff, it would help me to explain to you (&any others) what's going-on here.

This is the one in my service manual, but I think it's for the round headlight??