450 Mark 3 ingition wiring

[JimF]

Wires? For some reason I thought it was just one that burned up.

No headlights or horn? Pick one or the other and troubleshoot it one problem at a time.

You can't see volts or amps but you can measure them. Volts are way easier to measure. Measuring amps is difficult. That's another lesson.

Think of the wires as water hoses. The amps are like the water running through the wires which are like the hoses.

Water won't run through a water hose unless there is some water pressure to push it. Voltage is the pressure that pushes the amps through the wires.

Also keep in mind that water won't flow through a hose unless is has somewhere to go. if the hose was plugged on one end, water would still not flow through it even though there is water pressure trying to push the water. The water needs a place to exit the hose or it just can't move.

In your electrical system, the ground connection is the end of the wire "hose" that allows the amps to flow out.

I recommend that as you troubleshoot your problems you draw your own wiring diagram of what your bike has as it might not be the same as is in the manuals (previous owners may have changed the wiring around.)

Either your battery (engine not running) or your electrical generator/alternator (engine running) supplies the voltage (the pressure) to push current through your wires and through your headlight. But you likely have a couple of electrical things ahead of the headlight. There is probably a fuse and a switch before the headlight.

Hopefully you have a multi-meter that measures volts. Connect the meter's black wire to the frame and probe connections on the motorcycle with the meter's red wire.

With your power source (battery or generator/alternator working) measure the voltage at the fuse. Where the wire from the power source meets the fuse you should measure 12-volts into the fuse and on the other side of the fuse you should see 12-volts too. If the 12-volts is not on both sides try changing the fuse.

Probably the next thing in the path is the light switch. Measure voltage where the wire from the fuse connects to the light switch. You should measure 12-volts. Turn on the light switch (close the switch.) Measure the voltage at the switch at the wire going out to the headlight bulb.
You should measure 12-volts.

If you have a high-beam and a low beam, there will likely be three positions on the switch: Off, high-beam on, and low-beam on. That means one wire will bring amps into the switch and the switch will direct amps either to the high beam or the low beam. For this switch you can check that when you close the switch for "high-beam on" you should see 12-volts on the wire going to the high beam connection on the bulb. Likewise when you close the switch for "low-beam on" you should see 12-volts on the wire going to the low beam connection on the bulb.

If you have 12-volts at the bulb when either light switch is set to the "on" position the bulb should light up. If the bulb doesn't light, that means one of two things:

1) The bulb might not be grounded. Remember that without a ground connection the amps cannot flow through the bulb. If both the high beam and the low beam are not working but there is 12-volts on the bulb at both the high and low beam connections, chances are the ground connection is not being made. That would explain why neither high-beam or low-beam is working. The amps won't be able to flow out of the bulb and into the frame ground unless a ground wire is implemented to provide the "hose" for the amps to flow to ground.

Check the ground connection point on the bulb. It should read zero volts. This difference in voltage pressure (also called potential) across the headlight is what we want because the headlight will be doing work (lighting up) by using the difference in in pressure.

If the ground connection at the light bulb reads 12-volts the light is not working because there is no difference in pressure (potential) between the incoming 12-volts and the ground wire. Remember the bulb is where the work is going to be done. For this reason we have to have 12-volts of pressure at an incoming contact (high-beam or low-beam) and we should see zero volts (the opening at the end of the hose) as this is where the amps are flowing out of the headlight and into the frame (which serves as our drain for amps).

Motorcycles could use wires for ground connections, but the frame is metal and it's there and it's free. The frame then is for our electrical purposes just one giant thick wire that goes everywhere on the motorcycle. It serves as our the drain that the amps need for every electrical item on the motorcycle.

2) If you measure 12-volts going into the bulb, and measure zero volts at the ground side of the bulb, than another thing that could be wrong is that the bulb's filament (a wire inside the bulb that glows when amps run through it) is broken.

Let's just go from there and see what you find.

Jim

[double diamond]

Just to confirm something that seems to be getting assumed: this 450 has been converted to 12 volts? The stock system is 6 volt. A 12 volt battery in a 6 volt system would be a problem. Also, if it was converted to 12 volts I would expect some differences with the components and wiring.

Matt

[Jordan]

Yes, certain components would need to be changed when converted to a 12V system.
But the wires themselves would not. In fact, if headlamp wattage is the same, the current would only be half of what it was as a 6 volt.
So the wires would not be getting as hot, all other things remaining the same. Then again, with 12V there's the temptation to go overboard with lamp power.

Just to mention, Ducati switchgear, especially the High/Low beam dipswitch, is poor quality.
Good news is there's an excellent add-on fix : relays.

[Paddles]

Thanks fellas, just to confirm its a 12 volt conversion. Two wires coming off the same 15 amp fuse melted. I haven't been able to do much on it this week but am taking on board the ideas..thanks...and also found the basic wiring download to be useful as I understand a bit more about it. Dip switch is pretty new as there was some electrical rewiring/replacements parts done to get it registered and going about 18 months ago. The thing I picked up is to go slowly so I don't put thing back the wrong way--which is what happened with the ignition switch...P

[Paddles]

Rectifier/regulator coil issue?

Hi all. Thanks for previous help. I was checking my wiring for continuity with a multimeter (static) and the wiring seems ok now but there no current going from the current regulator unit to the coil and then the fuse/switch (battery is charged and hooked up correctly). The manual gives some trouble shooting tips for a 6 volt regulator but mine's a 12 v one. Even so, following the checks along the lines of the 6 volt one in the manual, there's seems to be an issue with the coils inside (I could easily be wrong here). So before I order a replacement unit, any ways to confirm its bad? Is it likely that's its an issue given the above/its age (probably 25 years old)? Is it repairable by a novice (I know that's unlikely)?

Thanks heaps again.

Paddles