Systems to Brighten Dim Lights on Alt.Powered models

[DewCatTea-Bob]

" I got why it'd work on the negative side but not why you'd recommend it be there instead of the positive side. "

____ Okay, I'm always willing to elaborate further! ...
While a main-fuse will do it's job on either side of the battery, (since it's the same ELECTRICALLY), one of my reasons for choosing the negative-side of the battery, is because it's ground-wire is usually connected to a grounding-point that's somewhere near the battery, which then usually puts the main-fuse in a more accessible PHYSICAL-location.
And also since Ducati already has fuses on the positive-side, I see no reason to put another fuse in direct-series with them!
__ Also, I neglected to add another one of my related experiences! ...
I recall one day when I was about 15-miles heading-out from home, on a highway,, I was cruising-along and everything seemed okay when all of the sudden the motor started missing & quickly died! _ I then thought to myself that I never had my motor quit so quickly by running-out of gas from my main-tank. _ I quickly turned-on the reserve-tank & coasted off the road, where I tried to restart. _ After failing to get the engine restarted, I got off and looked things over.
That's when I noticed that a side-cover had lost it's front mounting-bolt and the cover was hanging-down just enough to make contact with the POS-post of the battery! _ Thus it had shorted-out the positive side of the electrical-system so that there was insufficient juice to run the ignition!
Fortunately, the only thing that got fried, was just the battery's ground-wire! _ So I was able to get the engine going again (by sticking something I found on the side of the road between the side-cover & the battery), and return home to do a proper repair-job of the whole problem.
__ If I had had a fuse on the negative-side, then that ground-wire would not have burned-up it's insulation,, but a fuse on the positive-side would not have helped at all !
So you see, the POS.terminal on the battery is a dangerous area (on a negative-ground system), and with ALL fuses on just the positive-side of the battery only, then none of them can fully protect whatever grounding-connections you may have on the negative-side of the battery!
__ So I hope this now makes my point on this issue more clear.

DUKE-Cheers,
DCT-Bob

[JimF]

Regarding the fuse location, it is important to keep in mind what it is the fuse is intended to protect. I think in this case a fuse either coming off the positive lead of the battery and in series (ahead of) all the loads on the electrical system or on the negative lead of the battery between the negative lead and the motorcycle frame (here too in series but behind all the loads) is a 'shared' fuse and is intended to protect the wiring harness (and not any electrical loads in particular) against a catastrophic power surge, typically a direct short to ground. All the current (amperage) of the entire battery circuit is carried through that one shared power fuse. I refer to this as a shared fuse because all the current being distributed to every electrical load on the system is being carried through or shared in this one particular fuse.

The fuse is protecting against a very real danger which is that the battery can unleash a lot of current (amps), enough to make wires red hot, melt the copper conductors and burn the wire's insulation off in the case of a direct short. Wires are inexpensive but difficult to change given their routing under tanks and bodywork, and certainly not made easier by the side of the road. Fuses are cheap just like a piece of wire, but much easier to source and change by the side of the road.

The same current that leaves the battery has to re-enter the battery. Regardless of whether you consider the current as flowing from positive to negative or vice versa the shared power fuse will work in either spot, that is on the positive terminal or the negative terminal of the battery.

The fuse size should probably be selected based on the gauge of wire leading from the battery so as to limit the maximum possible current flow (limited by the fuse size) to some amount that is just slightly above the maximum ampacity of the largest wire in the harness, which by rights should be the wire coming off the battery's positive side and equaled in size by the wire attaching to the negative terminal.

Sometimes you will see a bare metal (sometimes braided) ground strap on the negative side of a battery leading to the frame. That can carry more current than the positive wire, so the fuse would then be selected for the maximum ampacity of the wire coming off the positive terminal and not for the ampacity of the ground wire (strap.)

This shared load fuse protecting the entire wiring harness against a catastrophic failure is not the same as a fuse intended to protect a single load or smaller gauge wires feeding individual loads. Since our Ducatis are negative ground systems wherein the frame is used as an electrical conductor connected to the negative battery terminal, the loads themselves are generally grounded (connected to the negative battery terminal) by their mechanical connection to the frame. This electro-mechanical connection provides no opportunity to insert a fuse in the circuit on the negative (ground) side of the load. This is why fuses for individual electrical loads are installed on the positive side of the load.

In Ducati Bob's method of placing his shared power fuse on the negative side of the battery, if either side of the shared power fuse should ever be accidentally shorted to the frame it will not blow causing a motorcycle-disabling inconvenience until a replacement fuse is sourced as would be the case if the fuse were placed on the positive side of the battery and it should be accidentally shorted to the frame.

In addition, the shared power fuse on the negative side of the battery does not require insulation at its connection points which will save cost. A fuse on the positive side of the battery must be carefully insulated from the frame.

[kmev]

Your schematic has nothing wrong with it ELECTRICALLY. _ I just note that your brake-light won't work unless the lights are turned on, and that there's a redundant line connecting the head & tail lights.

Yes, I've been thinking about rewiring it so the brake light will work whenever the key is inserted. There's been more than one occasion where I've ridden off with forgetting to turn the lights on. I also realize there is a redundant line for head and tail lights, but I made the schematic that way in this iteration so it more closely follows the original wiring schematic.

Your newly added details don't really reflect all the PHYSICAL-connections which your circuit-board & master-switch conveniently provide you with. _ I suggest that you take full advantage of all the circuit-board's terminal-connections which could serve your same needs.

I thought about drawing out all the phyical connections on my schematic, but then realized I didn't want to spend that much time trying to redraw everything so it was organized, logical, and still traced all of the switch circuits. If anyone wants to replicate this schematic it is very easy to figure out where everything goes with the switch board in your hand - and I did point out a few of the connections. I probably will take advantage of the circuitry to wire a brake light whenever the key is inserted, as well as allow for a horn and dimmer switch in the future.

I also learned a lot about fuses. I had no idea a fuse would be effective on the negative side.

The only problem is that it will be several months before I can report back as to how this all worked out. My bike is still in a thousand pieces, there's two feet of snow on the ground, and the temps are in the negative range.

[DewCatTea-Bob]

By kmev : ...
" Can I simply go to NAPA and get a 6v auto coil? "

____ For anyone interested, here's a link to what should be the 'GREEN'-labeled ign.coil.....

http://cgi.ebay.com/ebaymotors/DUCATI-E ... 2558578557

If the link is not live, then just search the 12-digit number at eBay.
__ Even though stated as "6-VOLT" , it should not be the 'RED'-labeled ign.coil meant for battery-powered models.
(SIDE NOTE: - If kmev bothers to post that he wants to win the above item, then I SUGGEST that the rest of us leave it be for him.)


FAIR-Cheers,
DCT-Bob

[kmev]

(SIDE NOTE: - If kmev bothers to post that he wants to win the above item, then I SUGGEST that the rest of us leave it be for him.)

Bid away - I'm going to use my existing Japanese coil.

[DesmoDog]

The 4th-wire will need to be (electrically & physically) connected to one of the two AC-inputs of a full-wave rectifier -(FW-rect./bridge-block) that's rated to handle at least 6-amps & 50rms-volts. - (NOTE, such a 'FW-Bridge'-block that just meets these minimum-requirements, may actually cost more than the more popular such unit which is rated at 25amps & 200 Peak-Inverse-voltage, (and is "block" shaped @ 1" x 1" x 1/2" thick with a 1/4" mounting-hole through it's center, and also comes with handy spade-connector terminals, often found for under just 3-bucks!)

Is this an example of what you're talking about?



http://www.allelectronics.com/make-a-st ... R/-/1.html

[DewCatTea-Bob]

" Is this an example of what you're talking about? "

____ YES, indeed it is! _ Not sure if this brand has the 1/4" mounting-hole, however.
I used to get FW.Bridge-blocks like these but with metal-casing & center-hole, which I would thread with a 1/4-20 tap, so that it could then be easily bolted-down to it's chosen mounting-point.
__ BTW, this rectifier-block
(along with a toggle-switch much like that "D & B" switch which you posted about, from that non-Ducati headlamp on your 160),
is all anyone really needs in order to convert their wide-case DUKE to a 12-volt charging-system!


Fun-Cheers,
DCT-Bob

[kmev]

That looks just like the one I got from Radio Shack, but mine is all plastic (it does have the center hole).

[bettyann]

Dew cat tee bob.
I have 2 questions:
#1 I picked up another 65' scr, 6v28w, flywheel # 31 20 95.cheap! I took out the stator to see the condition of it, and the wires.
The wires are so rotten and oil soaked, it's impossible to tell the colors. looking at the fiber wire connector board on the stator.
Is the white in the center of the board,and the yellow to the left of it? and the red to the right wired to the 1wire coil correct?
And once you mentioned the ohms reading to test the coils to see if they are still good.What are they?
# 2 I'm restoring a 65 bronco, it has a 6v28w alternator and somewhat the same wiring system as the 160 Monza.
Except that it's got a flat 2 finned air cooled diode,(rectifier) E-50-2.2a-BF. And a transformer looking Impedance coil,
Aprilia part #031411., Some one removed the wires in the headlight, so I don't know how to rewire this impedance coil or the rectifier. The lighting coil has one wire,and the feed coil has one wire.Do I hook the lighting coil to the head light/taillight,
and splice the rectifier (ahead of the lights) and connect through a switch to the battery to recharge for horn& stop lite?
What do I do with the Impedance coil? This stuff is easier for you than me, I also researched the brass flywheels, Flywheel # 31 20 95 & 31 20 92 are for the 6v28 watt system. the 31 20 94 is for the 6v40watt system. Thank You. Capt Paul

[DewCatTea-Bob]

NOW EDITED for better sense!
DCT-B.


" it's impossible to tell the colors. looking at the fiber wire connector board on the stator.
Is the white in the center of the board,and the yellow to the left of it? and the red to the right wired to the 1wire coil correct? "

____ Gee it's been so very long since I've had one of those stators in hand, that I really can't recall for sure. _ But I'm thinking that the left-alt.coil is the (fatter) ign.power-coil (which has somewhat thinner gauged windings & only one lead out from it [that's to be connected to the YELLOW-wirelead] ), while the right-alt.coil is the charging & lighting power-coil, which should have the two (separate) leads for connection to the WHITE-wirelead & the RED-wirelead.
But, from what you ask: "and the red to the right wired to the 1wire coil",, it's seeming that you may actually have the "40-watt" stator, (since the 40w-alt has a single coil-lead [from it's right-side coil], that's connected to the RED-wirelead!).
__ Even without the original colored wire-leads attached, it's not too hard to tell the 28w from the 40w stator, (especially with the use of an ohm-meter!)...
You see, while both stator models have a YELLOW-wirelead for the ign.power-coil, and a RED-wirelead for the lighting power-coil,, BOTH also have a WHITE-wirelead, which is involved completely differently, for each model ! ... While the WHITE-wirelead for the 28w-alt is connected to the same (right-side!) power-coil as the RED-wirelead is connected to,
the WHITE-wirelead for the 40w-alt is connected to the same (left-side!) power-coil (& winding) as the YELLOW-wirelead is!
In the case of the 40w-stator, ONLY the lighting-coil's winding is grounded to the stator, (while it's ign.power-coil's winding is only connected to the yellow & white wireleads!).
__ Since your wireleads need to be replaced anyhow, I highly suggest that you cut-open their black-conduit & uncover those 3 original wireleads, to see what the actual colors are, connected to each coil's lead-end,, and then be sure to note that info for us, so I can then get things more definately straightened-out for us.
Got any pix?


" And once you mentioned the ohms reading to test the coils to see if they are still good.What are they? "

____ You need a meter which can read under 1 ohm ! _ And the readings can't tell you that the coils are "good", but only, possibly, if they're bad.
I can't really recall the exact readings which each winding should have but, I think it was like .3 ohms for the WHITE, .6 for the RED, & .7 for the YELLOW, (to ground of the stator-plate, in each case).
If you can get consistant readings (after checking each winding at least twice), then please let me know what readings you got with your ohm-meter.


" I'm restoring a 65 bronco, it has a 6v28w alternator and somewhat the same wiring system as the 160 Monza.

____ I don't recall if I ever knew that that model had a '28w' alternator but, I do know that it was not the same as that which was used on OHC-models!
Back in the '80s, I could have been more helpful with the Bronco models, but I never worked with them enough to still recall much about them. _ I can still try to help ya with external electrical questions though! _ But please try to make it easier for me by asking clear & direct questions about each circuit separately. - (As opposed to just dumping-out thoughts for me to then have to try to properly organaize.)


" And a transformer looking Impedance coil, "

____ The impedence-coil is used as a kind of AC current-regulator. _ It has little resistance to DC but, with AC, the HIGHER the AC-frequency, the MORE resistance that coil has to current-flow!
So that impedence-coil is helpful because, the alternator has two (undirectly related) effects on it's AC-output as RPM increases... Not only does the AMOUNT of power-juice increase, but so does the FREQUENCY of it's AC-waveform!
So at the same (high RPM) time when excessive power-juice would otherwise be dumped into the load-system, (since the excessive power-juice is also at a higher frequency), the effect of that choking-coil then tends to dampen the flow of the (higher power & higher-frequency AC) power-juice! _ So ya can understand how that impedence-coil can conveniently have LESS effect when the alternator is producing lower power (& lower frequency AC), and yet also have MORE effect when the alternator is producing higher power (& a higher frequency). _ It's like having a varying resistor that automatically increases as excessive power does!
__ (Side-note: Where-ever I state "power-juice", most others would simply say 'current', however, "current" -[amperage] is simply a measure of the FLOW of any amount of electrons, while "power-juice" is the actual electron-energy -[both any quantity + it's force], which moves through wiring to the 'load' [at which point it's called "wattage"!]. _ 'Wattage' is a measure of the amount of the POWER of 'electrical-energy' -[which when moving through wires, I then simply prefer to call it "power-juice"] . )


" I don't know how to rewire this impedance coil or the rectifier. "

____ Sorry I can't tell you exactly how they were wired-up on the Bronco! _ But I'm sure the diode was used the same way as for the 160.
The choke-coil was either used to help protect the light-bulbs (from burn-out), or, (if the charging-circuit was much stronger than the 160's), to make life easier on the battery, (but I doubt this is the case here).
Since the choke-coil is located in the headlamp-shell/bucket, I'd expect it was connected to the main-lights headlamp-switch.


" Do I hook the lighting coil to the head light/taillight,
and splice the rectifier (ahead of the lights) and connect through a switch to the battery to recharge for horn& stop lite? "

____ I'm just not sure but, if it's alt has only two output lead-wires, then that seems like the only way to go. _ (The battery won't then charge as well [when lights are used].)
Why not ask a fellow Bronco-owner how his looks to be wired? _ (I sold my stock-Bronco to a fellow-member who's registered here!)


____ Do you think you'll care to make-up a wiring-schematic for your Bronco-project?


Hopeful-Cheers,
-Bob