Adding headlight and tail light - best way

[STEVENM63]

I just got a '65 250 bitsa that built as a racer and has no lights. It is a magneto bike and I would like to add a headlight and tail light to make it street legal. What is the best way to do this? I was thinking about just using a 12V Li-ion battery and setting up a dedicated circuit to power a standard 55w headlight and maybe a LED tail light. Cognito Moto has a 30w LED headlight that works in a 5/75" headlight which I am also considering. So the plan would be to just charge the battery each time and expect about 2hrs of out of it.

Are there any other suggestions?

Steven

[JimF]

I would suggest a test ahead of time.

Forget the taillight for the test. Buy the battery and the 30 watt headlight. At 30-watts the headlight will pull 2.5 amps from a 12-volt battery. Fully charge the battery and put the headlight on it where you can watch it while you do something else for a while. Time the life of the battery as it feeds the headlight and when you think the headlight gets too dim get a fix on how long a time it lasted.

The brake light won't add too much more drain, particularly because it isn't on most of the time. The running light will be so it will shorten the battery run-time but just a little.

At least you are being realistic with your expectations. If you are not planning on using the light for illumination of a road at night, and are just looking to have a headlight for legal daytime compliance, you could think about pulse width modulating (PWM) the headlight. Neglecting a minimal power loss for the PWM circuit, if you were to turn the LED on and off faster than the human eye can detect, you might be able to have it on 50% and off 50% of the time (50% duty cycle) but the human eye won't be able to discern the oscillation, or perhaps it will look like you are running one of those headlight flasher units.

The real point of it would be that if the headlight is only on 50% of the time you could expect to get almost twice the run time out of the battery.

Jim

[DewCatTea-Bob]

[quote"STEVENM63 ...
" I just got a '65 250 bitsa
and has no lights. It is a magneto bike "

____ So then if it's actually correct that your Duke-model is either a 1965 Scrambler or Mark-3, then it's 4-pole alt.mag should have a stator-cable with three wire-leads -(being 1-red; 1-white; & 1-yellow) !



" and I would like to add a headlight and tail light to make it street legal. "

____ The stock lighting-coil can do that (as it was originally meant to, by the factory),, but to be rather nicely 'street-legal', you may also care to add a brake-light & horn powered rather by a battery.



" What is the best way to do this? "

____ The answer to that is very dependent on exactly what YOU specifically want to accomplish and the funds you're willing to spend to get as close as you can to your goal !
You may consider going the same (expensive) route as fellow-member 'Nick' has, (with an aftermarket charging-system installed on his Mark-three), which just might be the "best" way to go.
__ Alternatively, there are many possible wiring-schemes to choose from that make-do with the stock power-system parts, and may merely adequately do the job well-enough to meet your minimal needs, (although not the "best" way you could possibly do with alternate parts).
Here follows a link to a fairly closely related thread which you may wish to check-out & consider, so as to possibly help you narrow-down your options... viewtopic.php?f=3&t=1781



" I was thinking about just using a 12V Li-ion battery and setting up a dedicated circuit to power a standard 55w headlight and maybe a LED tail light. "

____ That particular plan is-not one which I-myself would ever conceive & construct but, it's certainly doable and also doesn't really have-to be such a completely 'total-loss' lighting-system,, as at-least one of the alt/mag.power-coils could help the battery run the lights (so that the battery then wouldn't run-down as soon) !
But unless you can find a place to install a pretty-large battery,, a "55w" light is pretty-much unrealistic since the stock (so-called '40watt' ) alt/mag can only muster-up about 50-watts MAXIMUM* to spare (for other than ignition).
(* Near top-RPM.)



" Cognito Moto has a 30w LED headlight that works in a 5/75" headlight "

____ Very interesting ! _ A "30" watt 'LED' light ought-to be VERY-bright !
Can you provide a picture or anymore data on it ?



" So the plan would be to just charge the battery each time and expect about 2hrs of out of it. "

____ You really shouldn't have-to deal with such a poor & undesirable compromise !
Doesn't your motor still have it's alternator/magneto ?



" Are there any other suggestions? "

____ I'm sure I'll have a few,, after you confirm that you have a stock alt.power-plant, and
provide a more detailed explanation of what you hope to minimally accomplish from your electrical-system.


Hopeful-Cheers,
-Bob

[STEVENM63]

My bike has 3 wires coming from the motor. Right now only the red lead is being used, so it would appear that the other two are for the headlight and tail light/brake light circuit. From what I have read in the workshop manual, with this set up the headlight fluctuates in intensity corresponding to the engine's rpms.

Based on this info, what would you suggest. My needs are simply to have adequate lighting to make the bike street legal and safe to ride on city streets at night.

The 20/30w LED headlight is here: http://cognitomoto.com/collections/fron ... cts/h7-led

[DewCatTea-Bob]

[quote= STEVENM63 ...
" My bike has 3 wires coming from the motor. Right now only the red lead is being used, so it would appear that the other two are for the headlight and tail light/brake light circuit. "

____ We're left to continue assuming that your motor has the '40-watt' 4-pole alt/mag.model that has three wire-leads (which are of the same colors as that of the '28-watt' version). _ But whichever of those two 3-wire model-versions you may actually have,, in either case, the red-wire is MEANT for the lights, (NOT the ign.system !) ! _ (It amazes me how so very-often general-people/tinkerer-types will connect-up the WRONG wire-lead to the ign.coil, [since only it-alone connected-up by-itself, will readily provide ign.spark]!)
If the red-wire is left connected to the mostly SHORT-circuited ign.circuit for too-long, it's associated power-coil overheats and the insulation-coating (on that 'lighting' power-coil) will eventually become burned to a dark-brown and lead to lessened functionality. _ So you ought-NOT leave it connected-up that way for very long !
__ That you haven't yet realized that the yellow-wire & white-wire are both meant for the ignition & brake-light circuit,, indicates that either you haven't yet read-through the related thread which I had provided a link to, or didn't grasp the related info provided.
Hopefully, where your workshop-manual has apparently failed,, I will be more successful at correctly guiding you (as to what's-what).



" From what I have read in the workshop manual, with this set up the headlight fluctuates in intensity corresponding to the engine's rpms. "

____ It's certainly true that the stock AC.powered lighting-system gets gradually brighter accordingly with increased engine-RPMs, but really noticeable fluctuation doesn't occur except down near idle-RPM.



" Based on this info, what would you suggest. My needs are simply to have adequate lighting to make the bike street legal and safe to ride on city streets at night. "

____ Well what I'd first suggest is trying-out the stock lighting-system, to see if it possibly meets your minimum expectations. _ And if it does, then why-not go with it ?
To check & see, connect-up the red-wire to your headlight and see if you're okay with the resulting light-output. - (Of-course you'll also have-to ground the white-wire and connect the yellow-wire to the ign.system, [as stock],, so the engine will still be enabled to run.)
__ The stock brake-light setup however, has always been problematic,, and-so I would-not recommend continuing with that factory-RIGGED circuit-setup. _ Although I'd be glad to tell you exactly how it's wired-up, if you really wish to try-it-out,, (providing you have the correct type of brake-light switch !).
Otherwise, if you're willing to install a battery,, you could then trust to have a rather NORMAL-operating brake-light, and also a regular horn.



" The 20/30w LED headlight is here: "

____ Thanks for the link !
Unfortunately it doesn't tell of being available in 6 or 12 volt versions,, AND-also, I find it's 65-$ price to be uncompetitive !
__ That rather power-hungry LED-type light won't be able to consume more than 50% of the available power from the stock AC.power-source ! _ So if you aren't satisfied with the light-output from your stock-system,, then I'll tell you exactly how to full-wave rectify the grounded lighting-coil's power-output, and specially connect it properly, so as to run such a LED.headlight.


Hopeful-Cheers,
-Bob

[STEVENM63]

My apologies, but electrical is not my forte. Mechanical elements I easily understand.

So, digging a bit further it appears that the wiring was modified and replaced. I stripped off the newer insulation to find 3 wires (red, white, green). It appears that this was someone's idea of a salute to Italy perhaps. Anyway, currently the red wire is attached to a kill switch which continues to the coil.

My question is can the nature of the other wires (lighting, brake) be determined without having to take the case apart and trace them back to the source?

[DewCatTea-Bob]

[quote= STEVENM63 ...
" it appears that the wiring was modified and replaced. I stripped off the newer insulation to find 3 wires (red, white, green). "

____ Unfortunately whenever anyone alters any of the original colors of the factory's chosen wire-colors, then none can be trusted any-longer to actually still-be as ought be ! _ So-thus in this case, your green-wire might've simply been substituted for the original yellow-wire and the other two were rather logically left to remain factory-loyal, OR perhaps all of the three replaced wire-colors were randomly connected to the alt.stator. (?) _ So this uncertainty needs to-be checked-out !



" currently the red wire is attached to a kill switch which continues to the coil. "

____ If that replacement/red-wire was kept factory-loyal, then it's supposed to be intended for the main-lights circuit. _ However if it's rather been substituted for the proper/stock ignition/yellow-wire, then ign.spark can't be generated unless one of the other two alt.stator wire-leads (normally white) is grounded !
So are either of the other two replaced wire-leads connected to ANY-thing at all ?



" My question is can the nature of the other wires (lighting, brake) be determined without having to take the case apart and trace them back to the source? "

____ YES... providing that the person who replaced the stock-wires didn't also modify the alt.stator in some way ! ...
__ If you have an ohm-meter or continuity-tester, then we ought-to be able to determine which replacement-wires replaced which stock-wires. ...
ORIGINALLY, (assuming a '40-watt' alt.mag), the stock red-wire was connected to the lighting-coil, which was grounded,, so-thus continuity should be found between the red-wire & ground, (but not between the red-wire & either of the other two).
And for the original/stock yellow-wire & white-wire, those two were connected to the ign.power-coil,, so-thus continuity should be found between those two wire-leads (but not to ground !).
__ If you don't fully realize what-all the above implies, then alternatively, you could go-ahead & check for continuity between each of all-three wire-leads with one-another and-also with ground,, and-then after telling me the test-results, I'll then tell you which replaced wire-color is for which circuit.


Hopeful-Cheers,
-Bob

[STEVENM63]

Bob, thanks so much for you comments. It appears I have a mystery on my hands to solve before I even consider lighting.

Currently the red wire is connected to the ignition. The ends of the white and green wires were not connected to anything, just wrapped in insulation. I did run the bike for a few minutes with this configuration. What is the testing procedure that I need to perform with my meter to determine the state of the other two wires?

Thanks,
Steven M

[JimF]

From what I have read in the workshop manual, with this set up the headlight fluctuates in intensity corresponding to the engine's rpms.

Based on this info, what would you suggest. My needs are simply to have adequate lighting to make the bike street legal and safe to ride on city streets at night.

I believe this is because your electrical system uses unregulated AC voltage.

From the onset you must accept that your electrical system is weak. Bob will argue how weak, but let's just say it's weak.

Ducati rated your system at 40 watts of power and if we accept that number remember that the 40 watts has to serve the headlight, the brake light, running light and the ignition system all at the same time (worst case condition.)

For you to have lights at idle, you will need to rectify the AC to DC, and then store some of that DC power in a battery when you are driving and the RPMs are high and the engine is generating good electrical power so that when the engine idles and the voltage being generated by the engine dwindles the battery will spit out some of the stored power and keep the lights bright.

This is only for the lights, I would keep the ignition circuit AC.

Because you are thinking of using LED components, you have to convert to DC anyway and you should regulate the DC so that you don't over-voltage the LED components and destroy them.

Jim

[DewCatTea-Bob]

[quote= STEVENM63 ...
" It appears I have a mystery on my hands to solve before I even consider lighting. "

____ Now enlightened by info contained within your latest-post,, I'm no-longer sure I agree with that conclusion, depending on exactly why you're thinking that.



" Currently the red wire is connected to the ignition. The ends of the white and green wires were not connected to anything, "

____ Then in that case, the red-wire probably must be connected to the grounded alt.power-coil that was originally meant for powering the main-lights, (thus loyally remaining colored as stock),, as the ign.system could-not function without a completed ground-circuit ! _ And since you've indicated that the other two alt.stator wire-leads aren't connected to ground, then that tends to confirm that the power-coil intended for the ign.system is-not being used as originally intended.



" I did run the bike for a few minutes with this configuration. "

____ Not to worry much about that, as the heat-toll on the lighting power-coil's insulation-coating is only damaging in a rather long-extended accumulative manor. - (As one-day we may hear-about from Jim, [as I believe he's still in a testing-stage to discover how many hours his lighting-coil will remain fully functional while left connected to the magneto-type ign.system].)



" What is the testing procedure that I need to perform with my meter to determine the state of the other two wires? "

____ You need to connect the leads of it's ohm-meter to the green-wire & white-wire so as to confirm that they have continuity of less than 1-ohm, (and-also, confirm that there's NO continuity between either of them & ground [by contacting the meter-leads to ground & either of the two wire-leads left in question] ). _ Then we will pretty-much know for-sure that the replacement/green-wire was meant to replace the stock yellow-wire,, and also, that the other two replacement wire-leads were rather-logically meant to remain loyal to the original factory-chosen wire-colors.


Hopeful-Cheers,
-Bob