Ducati 160 Electrics question(s)

[DesmoDog]

" I forgot to check if the new ignition switch can even be wired as shown... "

____ Concerning that, I assume you're referring to whatever switch is part of that non-Ducati circuit-board which you had previously posted a pic of... correct? ...
__ As seen in the factory electrical-scheme, (which you also now have posted), that which represents the handle-bar switch, is quite difficult to determine which electrical-connections correlate with it's physical-switches!... Yet in your two wire-diagrams, it appears that you've attempted to indicate the possible pathways through that switch. ...
So if you have done that with confidence, then could you also do the same with that non-Ducati switch, (providing that you intend to make any use of it), ?
As it would be helpful to also see a circuit-diagram of that as well !

Yeah, I'm talking about the non-Ducati ignition switch shown and it is the one I'm going to use

I'll have to work on diagraming that switch. I have notes, but don't have them with me right now. WRT the handlebar switch, I'm pretty confident of the wiring in that. I didn't want to spend much time doing an accurate schematic of it as basically the AC in feeds the running lights and the DC in feeds the parking light. On the handlebar switch the top lever determines running/none/parking lights. Side lever determines high and low beam. Button grounds horn. But then, I'm guessing you already knew that.

[DewCatTea-Bob]

> From DesmoDog's 1st Feb.11th post .....

" 1) The parking light option is moot, I'll never use it. "

____ The handlebar (160 master) switch lets the lights be run by either the battery-juice, OR the alt.juice ! _ I think you ought to consider (and seem to be interested in) retaining that neat option.


" 2) Is the AC input for the horn ok? Can I tie into the red or 4th wire before it connects to the rectifier? "

____ I don't understand the reason for that circuit... The stock-horn is 'DC' (powered by the batt.), are you intending to use an AC-horn ?? _ (Or did your eye just slip while tracing the stock horn wire-scheme?)


" 3) The lights used to be AC powered. If I connect both "power in" leads on the handlebar switch to the DC power, everything should work. "

____ That's quite correct! _ That versatile 160-switch would then be relegated to send only DC-juice to the lights in either MAIN or PARKING positions.


" 4) The switch on teh side of the shell isn't used for anything, neither is the second indicator lamp. I'm ok with that. "

____ Even so, it would be nice to give them a use! _ (I'm sure I could think of something for you, if you like.)


" Main reason to do the mod is I want to run the lights off the battery and don't want the battery to go down around town... "

____ The stock-160 electrical set-up barely charges the battery well enough to keep it charged while running the tail-light & "town/parking-light". _ So to run the head-light by the battery as well, requires a modification for keeping the battery charged! ...
You could full-wave rectify the AC power-juice of the alternator's LIGHTING-power-coil, (which is the best way to go), for helping the battery run the lights,, or you could (more simply) tap-into HALF* of the AC power-juice made by the alternator's IGNITION-power-coil, (*that's actually unused & wasted by the stock ignition-system anyhow!). - The 'break-even'-RPM won't be as low but, you could get-by with it using a 25-watt headlight.
(I believe the thread I've been using with/for 'Desmoto-M.3', covers that system-modification.)


" As I see it, witht his set up the lights will work with teh engien off and the engine will run with a dead battery, correct? "

____ Correct. _ Just as does the stock 160 set-up! (Pretty NEAT!)


" I'm staring at this and thinking... if the engine is running, the only reason to turn the key would be to allow the battery charge? And with the key off, there is no fuse in the system? "

____ I'm not sure I'm following you on this. - (Don't know where you're looking at for sure.)
If you're referring to YOUR 1st scheme, (not the stock one), then you should keep in mind that the stock key-switch performs two SEPARATE circuit-connections at once, with the insertion of the key! ... While the key's use CONNECTS the battery to it's various loads, it also UNconnects (a kill-switch) at the same time, and is used to UNground-out the ignition's power-juice! - (As a normal 'kill-switch' in unactivated-position.) _ Thus THAT circuit-connection is COMPLETED when the key is OUT! - (NOTE that your diagram indicates THAT switch-circuit as if key is INSERTED, thus braking that circuit & allowing spark! _ While AT THE SAME TIME your diagram also indicates the battery/load-circuit of the key-switch, as if key were REMOVED!)
ONLY the battery/load-circuit is COMPLETED when the key activates it's STOCK-switch. _ So hopefully your replacement key-switch can not only do just that normal operation, but also make another circuit-connection when the it's turned-OFF.
Also, the only thing that TURNING the stock-key, (after being fully inserted), does,, is keep it held in place!


" I need to see if the key can disconnect three things at once,"

____ Right, to connect & disconnect 3 separate wire-leads also with one action, would be a bit useful, as well !


" and do I consider adding smaller fuses for separate functions? "

____ A 30-amp fuse on the battery-ground side would be sufficient by itself but, it could be useful for trouble-shooting purposes, to use a 15-amp fuse for the horn & brake-light circuit, and also another 15-amp fuse for all other lights. - (Perhaps even an extra 2-amp fuse for the instrument-lights & long run back to the tail-light.)



> From DD's 2nd Feb.11th post .....

" I don't see much reason for a battery at all with the stock set up... parking light? "

____ The battery was NEEDED not just for the 'TOWN' / parking-lights function, but also (primarily) for the brake-light & horn !
And if-I-were-you, I'd take further advantage of the battery by wiring the high-beam to light-up when the brake-light does. - (Ya just need a cheap diode to keep the brake-light off when-ever the high-beam's turned-on.)


" I have to decide how much a no engine = no lights set up would bother me... "

____ I don't see why, as that would only have to happen when your battery is out of charge!


" I suppose I could set it up so the "park" position lit up the head light and tail light too... "

____ The park-position already lights the tail-light, so all that's needed is to simply jump-wire to the Hi/Lo-feedwire, for lighting the head-light as well.


" so then the second indicator could show I was running off the battery and not the alternator... "

____ That'd be sorta neat! _ And I'm sure there's at least one way to accomplish that but, how were YOU thinking of doing that? _ With another twin-switch? _ (I can see where using a diode would allow it to light-up with AC & not with DC.)



> From DD's 3rd Feb.11th post .....

" but here's one that disconnects the battery and the rectifier from each other and the rest of the system,
Am I correct in thinking that if the rectifier is left connected to the battery, it will drain the battery when the engine isn't running? "

____ Rectifier-diodes are weird in that they have very little resistance one way and a whole-lot the other! _ But unfortunately, they're NOT like a perfect reed-valve, without any (reverse-flow) leakage! _ So thus they do tend to drain a battery (SLOWLY but surely!). _ So while not real necessary, (Ducati didn't bother), it's nice to break any rectifier's connection from the battery's circuit when not in use.


" As I see it - this system would allow the lights to work with the engine not running if there is a charged battery, and also allow the lights to work with no battery if the engine is running? "

____ That's correct! - Both with the stock set-up (using DC & AC), and with the set-up which you have diagrammed (using DC & PDC).


Fun-Cheers,
DCT-Bob

[DewCatTea-Bob]

From DesmoDog's Feb.12th post .....

" On the handlebar switch the top lever determines running/none/parking lights. Side lever determines high and low beam. Button grounds horn. But then, I'm guessing you already knew that. "

____ I always try to word my responding-posts so that they will also make sense for other readers as well, (at the expense of over-answering with added info which I would assume the person who I'm addressing probably already knows of, to some degree). _ So it's fine that you have done the same here.
However in this case it seems that it could be that you had mistakenly thought that I was ASKING about the stock handlebar-switch's circuits... Where-as my actual purpose, (for pointing-out that YOUR depiction of that handlebar-switch was more useful than the factory's), had been meant to indicate that since you were capable of figuring-out the circuits of that handlebar-switch (with an adequate degree of confidence), THEN you ought to ALSO be quite able to figure-out & correctly depict the circuit-pathways of that non-Ducati circuit-board -(which I know next to nothing about).
And thus if that's indeed the case, it would then be nice if you could also post your depiction of that switch-board's circuit-pathways, as well. _ (Providing that you'd like me to confirm or suggest ways for you to take advantage of what-ever it's capable of.
(These above thoughts are all I had meant to convey/inspire within that previous posting.)
___ Indeed I've worked with all OHC-DUKE's electrical-systems & their related switches enough to have had them all (except 175 & early 200s), memorized in my head ! _ (Otherwise I would've never claimed myself as a "Top-EXPERT" on OHC-Ducati-singles -[DUKEs] ! )
Also, I've altered or modified the systems of about 80 DUKEs!


Clarifying Cheers,
DCT-Bob

[DesmoDog]

> From DesmoDog's 1st Feb.11th post .....

" 1) ____ The handlebar (160 master) switch lets the lights be run by either the battery-juice, OR the alt.juice ! _ I think you ought to consider (and seem to be interested in) retaining that neat option.

" 2)___ I don't understand the reason for that circuit... The stock-horn is 'DC' (powered by the batt.), are you intending to use an AC-horn ?? _ (Or did your eye just slip while tracing the stock horn wire-scheme?)

" 4) The switch on the side of the shell isn't used for anything, neither is the second indicator lamp. I'm ok with that. "

____ Even so, it would be nice to give them a use! _ (I'm sure I could think of something for you, if you like.)


> From DD's 2nd Feb.11th post .....

" I don't see much reason for a battery at all with the stock set up... parking light? "

____ The battery was NEEDED not just for the 'TOWN' / parking-lights function, but also (primarily) for the brake-light & horn !
And if-I-were-you, I'd take further advantage of the battery by wiring the high-beam to light-up when the brake-light does. - (Ya just need a cheap diode to keep the brake-light off when-ever the high-beam's turned-on.)

Ok, it's late, I"m fading fast, and there's a lot of info here so I'll probably only hit some of it before heading off to bed...

1) I must have missed that the parking light option lights the tail light too... I'll have to look at the switch again (though it does make sense that it would)

[threadjack]tee hee hee... I usually keep the door to this room pushed (almost) closed but not latched when I'm on the computer late at night. My dog Desmo (hence my screen name) will sometimes push the door open and come in to join me. Anyway... I just heard him run into the door. But tonight it's latched. Sorry buddy![/threadjack]

2) D'oh! My bad. Traced the wire wrong.

4) My latest scheme (shown below) is very close to stock with no alternator mods, and uses the "other" indicator to show the parking light is turned on.

I hadn't thought of the brake light + high beam option, it's something to consider. There will be a front brake light switch to tap into so it wouldn't be much more wiring either...

Now about the key switch I'm using. Inserting the key does break the ground and allows the ignition to spark. However, the fixed end (non-switching end) of that switch grounds to the headlight shell through the mounting screw, so I'd intend to use the insertion of the key to break the ignition ground only. Basically inserting the key breaks the ground on one pole and grounds out another instead. I'm not sure how to exploit that for some other use? I haven't drawn out the functions of the switch yet because I'm too tired at the moment... It's after 2am, I should be in bed!

The other function of this switch does require it to be turned - that's the function I'd use to connect the battery to the system. The newest diagram is drawn so the key is inserted but not turned. Also, I can not disconnect three poles by turning the key so the switch would not work as shown in an earlier diagram.

I'll study the ignition switch a little closer to see if I'm missing something but I think the new diagram shown here is the most likely one to start with. No alternator mods, simple function for the switch... though I still may tie the headlight to the battery too.

And with that it's time for bed... more later whan I realize what mistakes I made tonight.


Edit: D'OH! I didn't indicate that the lead connecting the tail light and brake light bulbs is in fact the ground... I'll fix it tomorrow and reload the diagram...

[DewCatTea-Bob]

" Now about the key switch I'm using. Inserting the key does break the ground and allows the ignition to spark.
Basically inserting the key breaks the ground on one pole and grounds out another instead. I'm not sure how to exploit that for some other use? "

____ That's a fortunate coincidence for you!
So I understand that not only does inserting the key, UNground (& open) one circuit -(that's intended for killing the ign.),, but it ALSO grounds-out another circuit (which is kept open when the key is not inserted)!? _ If so, the only use I can think of for that unusual 2nd-function, is that it's used to allow the headlight-bulb to be grounded, (so that the headlight can't [normally] be left on & run-down the battery [without the key].)


" I didn't indicate that the lead connecting the tail light and brake light bulbs is in fact the ground... "

____ I took care of that little detail while adding stock 160 colors to your diagram! _ So let me post it for ya...





Hopeful-Cheers,
-Bob

[DesmoDog]

So I understand that not only does inserting the key, UNground (& open) one circuit -(that's intended for killing the ign.),, but it ALSO grounds-out another circuit (which is kept open when the key is not inserted)!? _ If so, the only use I can think of for that unusual 2nd-function, is that it's used to allow the headlight-bulb to be grounded, (so that the headlight can't [normally] be left on & run-down the battery [without the key].)

Hey... grounding the headlight when the key is inserted... I like that idea! Simply run the ground lead from the headlight socket to the "other" pole on the ignition switch. Consider it done.

I think I have new wire in most of those colors, and a couple old harnesses I can steal some from too. I may just start laying wires out on this thing today to see how the physical connections will work. I'd be pretty happy if I could get the switches all wired and the headlight "buttoned up" as it were.

Thanks for the headlight idea(s) and color coded diagram. When I work out the final details I'll repost something a bit less "messy", though considering I'm not using a stock switch I'm not sure how helpful it will be for anyone else.

BTW - do you ever sleep?


Edit: Taking a quick glance at the picture of headlight socket on page 1, the parking lamp and head lamp share a ground, so running it to the ignition switch would mean the parking light won't work with the key out either.

Edit again... I shouldn't post before noon... This headlight ground thing. The headlight only runs off AC with this set up. AC only runs when the engine is on. The engine only runs when the key is inserted... so the headlight can't be left on with the key out anyway, unless I power the headlight with the battery, which leads me down the trail to alternator mods again because now the alternator lead that did power the headlight isn't being used.

[DesmoDog]

So anyway...

I spent some time gazing at this ignition switch today.

The rotary function seems to work opposite of what I assumed, in that turning it counterclockwise seems to be the "on" position; "On" would be with the key angled to the left, while "Off" would be with the key straight, or aligned with the bike.

If I assume that the above is correct, it turns out that I CAN disconnect three things at once. I haven't got time to draw it out right now, but basically there are five poles on the switch. (Actually seven but only five are in use - one is just a transfer as it were and another isn't ever "hot", it's location is coincidental)

With the key to the left, all but one of the five poles are hot. So lets say 1-4 are hot. Let's also say that pole # 1 is "power in"

With the key to the right, Pole #1 (power in) isn't connected to anything, but poles 4 and 5 are now connected.

Bottom line is, I COULD use it with the diagram that uses a rectifier. But I'm still leaning towards the latest diagram (with a few minor changes)

[DewCatTea-Bob]

" the parking lamp and head lamp share a ground, so running it to the ignition switch would mean the parking light won't work with the key out either.
The headlight only runs off AC with this set up. AC only runs when the engine is on. The engine only runs when the key is inserted... so the headlight can't be left on with the key out anyway, unless I power the headlight with the battery, which leads me down the trail to alternator mods again because now the alternator lead that did power the headlight isn't being used. "

____ I actually hadn't meant to suggest that YOU use that unusual grounding-circuit for the exact purpose which I had guessed it could be used for. _ (Although if I were stuck with using that type of switch, then I'd certainly consider using it that way, for myself.)
Ducati's set-up used it's key-switch to not only activate the ignition (in the same manor), but also to allow the battery's positive-juice to become available for use (by other switches)... So since it seems that your non-Ducati switch doesn't have that exact same function, then you ought to have some other method to keep the battery-supplied system from being activatable without the key. _ Thus I think that strange switch was meant for grounding the battery! - (So that the battery's negative-juice won't be available [to ground] without the key!)
__ I do realize that there's a lot of functions to keep track of in one's mind all at once, and so when ya think of one aspect, it's then fairly easy to overlook/forget about another!
And trying to combine Ducati's scheme with another (unknown) cycle-company's scheme, certainly adds to the confusion! - (But I love this kind of complication, where there are multiple options to choose from & work-out a neat plan for !)
I've never found any use for the so-called "parking-light", so I always jump-wired it's circuit to light the low-beam! _ But you can't ride (for long) that way, as the battery won't run it that way (as stock) without getting run-down!
__ Anyhow, I've been neglecting to point-out that it seems that the Italians (back in the '60s) reasoned that HEADlamps were not needed (or even not allowed?) inside city/towns at night (as the street-lighting in such locations made 'headlights' unnecessary). _ I conclude this (unthinkable reasoning in the U.S.), because of what I've read (only) in many Italian-cycle owner's manuals... That the '0' - position is 'OFF', the '2' - position is 'COUNTRY-lights', and the '1' - position is for "City" or 'TOWN-lights' !
And, since that reasoning has not been acceptable within the U.S.,, the "1-position" has thus only been referred to as a "parking-lights" opition.
__ So, since YOU never use such a '1-position' light for 'parking' anyhow, and can't legally ride with such a dim light as that either, then just let it help light the speedo (when the lights are on). _ (And if it burns-out, if AC-powered, then switch that bulb to a 12-volt version.)
__ I bothered to colorize that last diagram of yours because that one seemed more like a keeper. _ I didn't colorize your added wires, such as those going the the two dial-gauges -(cuz for one thing, those bulbs may not cope with the varying AC-voltage), as you may end-up supplying their needed power from another (battery only) circuit.
(It looks more & more like you'll be needing to make use of every switch available in this project.)
__ I thought it would be somewhat helpful to color your diagram's wires similar to that which Ducati had used, but, I really don't agree with all the color choices which Ducati happened to use! _ And since your altered system won't be exactly as Ducati had it anyhow, I suggest that it would be okay to use more logical wiring colors.

____ As usual, while typing my thoughts down,, for each one I get typed, another one passes through my mind, and then gets forgotten by the time I get the thought I'm typing done!
So I only can hope that I got every one down, now. _ If not, I'll try to fill-in whatever I may have left-out, later. _ (As I usually do.)


Fun-Cheers,
-Bob

[DewCatTea-Bob]

" turning it counterclockwise seems to be the "on" position; "On" would be with the key angled to the left, while "Off" would be with the key straight,
basically there are five poles on the switch .
With the key to the left, all but one of the five poles are hot. So lets say 1-4 are hot. Let's also say that pole # 1 is "power in"
With the key to the right, Pole #1 (power in) isn't connected to anything, but poles 4 and 5 are now connected. "

____ Well, it seems (thus far), that not only was that (nonDucati) headlamp-switch made for a motorcycle which had non-battery powered ignition like the 160,, it was also made for use with a handlebar-switch that only controlled Hi/Lo & horn, (like a 250Monza).
__ Is there any sign of the "1_0_2" (positions) anywhere near that headlamp-switch handle?
(I suspect the "4 & 5 connection" is meant for the common 'parking-light' set-up.)
Though without a diagram of that switch's connections, I could only guess (in-the-dark) at what all the other poles were intended for.
But since #5 is dead in the "left" position and connected to #4 in the "right" position, then it must be that EITHER #5 is ALSO a 'power-input' (along with #1), (so that #4 could be powered by either source),
OR,
#4 is a sole power input, (for providing a single power-source to everything which gets connected to it).
And since there's already another ('D' & 'B') switch in the side of the shell-bucket, then I'd more-so suspect that #4 was meant to be a sole "power in".
__ So it seems that you have (at least) two different ways to possibly take advantage of that switch's two possible capability-choices -(of left & right connections).
This means that you have a choice of using the handlebar-switch as it was meant to be, or, let the headlamp-switch handle some of it's functions,, thus freeing some of it's more conveniently located switches for something else.


Fun-Cheers,
-Bob

[DesmoDog]

I'm going to wire the switch so turning it counter-clockwise is "on" and leave the handlebar switch as it was meant to be. I'm spending way too much time thinking about the "parking light" setting as it will never be used.

Today I was looking at the stock diode and while it looks intact, I want to replace it. It's mounted on a board that would need to be modified to fit the new headlight shell, and it just doesn't make much sense to me to modify a 45 year old part when I could put a new one in just as easily.

Domiracer has the diode listed for something like $14. Checking an electronic supply place lists a bunch of different diodes at much lower prices. I'm guessing the Domiracer part is a direct replacement for the old one, which I don't need since I won't be using the old board. So my question is...

How do I know which diode to buy, as in, what sort of specs would it need to meet?