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Okay before I go down a complete re wire route I would appreciate some advice / direction / confirmation if possible please.

DUCATI 907ie

Last year I was plagued with electric gremlins throughout the year winter, spring, summer and autumn, so much so that I probably spent a third of my time pushing the bloody bike on what rides I took on the bike. Each time was an electrical issue of some kind and the purchase of new rectifier(s), new coils, new battery, new fuse box, new starter solenoid, new earth and live wire lead replacements, a few partial short rewire projects or simply a few wire block cleans appeared to resolve the issue enough to suggest the problem was resolved.

IT WASN'T ??????

I know these are 20 year old Italian electrics but still this is now getting beyond a joke and means other projects have been shelved or abandoned.

The present state of play is this

The battery died as it was not charging on a run.

I checked everything but was aware that the charge light was not on with ignition so checked bulb and that was fine.

I then put a new rectifier on and this seemed to resolve the issue with a nice bright and correct charge light on ignition on, but...............

When I flipped the right hand kill button to on ready to press the start button it killed the charge light and blew the 15amp fuse in the left hand relay (closest to the blue block). The fuel pump was also dead. But the bike turned over on the starter and everything else worked but obviously wont start as the pump is now dead. All the leads to the fuel pump are perfect and wired correctly.

I then replaced the rectifier with the old one fitted and it was back to a dead to very dim ignition charge light and no charge from the alternator.

Where to next folks?

I have not yet done the upgrade rewire for the starter yet either before anyone asks.

Any help gratefully absorbed

Hi Stiv, I think I would remove all the body work and thoroughly inspect all the loom for chafing, bad earth connections and check all connectors are corrosion free. Another thing to check is the ignition switch, 2 off my Benellis have had to have new switches fitted in recent years because the were badly corroded on the contacts.
Hope this helps!

Did all that last year three times with the bodywork off each time and found a few small areas that I tidy up or re wired. I can't see it being the ignition switch as the battery light wouldn't be different.

I am going to re check all the earth points again I have the original rectifier sitting around somewhere which I will try. I also need to add that the battery light had worked fine on all three rectifiers when each was fitted.

Don't want to throw another £90 plus at another rectifier until I know for sure these are all useless.

I am wondering if the alternator is at fault? is there anyway of checking the voltage out of it in situ?

Yeah man , just kick her in the guts and put your meter across the batt and you should see about 13.5 - 14 vdc with about 3 grand on board . This will tell you if the whole charging system is working but wont really give any indication of battery condition . if there is an issue probly would be to check alt output at the alt , cant remember what it should be but it has been discussed here before ( I think its about 90 -120 vac ) and if that is ok your back to the reg/rect , but I wouldn't fit another coz ( sorta obviously ) there must be a reason for them to keep chundering............are you sure they are of a high enough capacity ?

Ignoring the alternator and regulator/rectifier. You wrote that the fuel pump is dead but the starter still turns. That's normal looking at the 907IE's wiring. If the fuse in the relay blows it will kill the power to the fuel pump and to the coils/iginition modules. The question is why it blew. Things that could cause this would be a short in the fuel pump or it's wiring, a problem in the ignition modules, the wiring to the coils or the wiring from the ECU to the ignition modules.

Did you replace the old coils with original ones? Same questions for the regulator.

You said you had replaced the fuse box. Is there a 25A fuse where the wire from the battery comes in and two 15A? Are they all still ok?

paso750 wrote:Ignoring the alternator and regulator/rectifier. You wrote that the fuel pump is dead but the starter still turns. That's normal looking at the 907IE's wiring. If the fuse in the relay blows it will kill the power to the fuel pump and to the coils/iginition modules. The question is why it blew. Things that could cause this would be a short in the fuel pump or it's wiring, a problem in the ignition modules, the wiring to the coils or the wiring from the ECU to the ignition modules.

Did you replace the old coils with original ones? Same questions for the regulator.

You said you had replaced the fuse box. Is there a 25A fuse where the wire from the battery comes in and two 15A? Are they all still ok?

What he says.

And as for the charging: What Hamish says about the voltage across the battery when the engine is running.
To check the alternator - disconnect the 2 yellow wires from the regulator. Measuring resistance across the 2 wires you should get quite a low reading, only an ohm or two. Measuring between any of the two and earth you should get no reading. With the engine running and meter connected across them set to read AC volts, you should read approx. 15 AC / 1000rpm.

also be sure to check the fuel filter.Clogged filters are the root cause of many dead charging systems on a 907

higgy wrote:also be sure to check the fuel filter.Clogged filters are the root cause of many dead charging systems on a 907

Shhhh , dont nobody ask how or why he he he

Shhhh , dont nobody ask how or why he he he

How ? Why ?

Cheers guys work away from home will have a ponder this weekend update Sunday night if able

Okay have tried all three of my rectifier's this weekend one gives me a nice bright charge light the other two a very dim one with ignition on with kill switch in off position.

The bright lit one is killed when I turn the kill switch to on ( and pump runs)

The other other two stay the same. (and pump runs)

Engine starts with all three now but more importantly there is absolutely no charge at the battery with the three different testers I utilised to confirm this.

I am going to take off the alternator cover and swap with a spare I have and then restart the whole process again.

Something about that smells real bad , even from here . ( gotta ask ) Are you sure you are wiring the rect/reg correctly , and are you sure you don't have another fault in the harness somewhere. I cant think why the kill sw would ( should ) have any effect AND the fact that it doesn't have the same effect on all 3 rect/regs , are all the rect/regs the same , do you have 2 of one and 1 of another . What Im getting at is that's its entirely possible that you have more than one fault . When logical steps ( swapping out rect/regs ) seem to a, not fix it and b, the inexplicable side effect ( charge light/kill sw )......there has to be another fault , and that kill sw thing could be a clue . I would want to find out why it does that . Just a thought , you havnt changed that charge light bulb for an LED ?

pleased its not mine

There is something very strange going on here. The regulator gets a 12v sensing feed from the ECU/Fuel pump relay on the brown wire when the kill switch is ON and the pump is running. The charge warning light should then be ON when the engine is not running. When the kill switch is OFF there is no 12V from the ignition circuit and the charge light should be OUT. I think there is some sort of wiring problem upstream of the regulator. The fact that there were problems with blowing one of the relay fuses kind of confirms this. Check that there is 12V at the regulator brown wire when the kill switch is ON and the pump running.
Also, there is no need to swap the stator to find out if it is faulty. Before digging in to the engine case do a check as I suggested in my previous post above.

My 2 cents here:

Years ago I had a 900ss loom I was working on and by mistake I swapped two connectors (one related to the right hand kill switch ) with another and the loom (and the bike!) caught fire as soon as I turned the switch to "run"; luckily enough my laboratory and the 1 gallon temporary tank I had hanging on the bike did not catch fire...

I wonder if in your case you swapped some connection and now you are getting some weird behaviour?

The other thing are the switches, sometimes they get stuck or internal bits get broken and short internally; it happened to me on a Paso I was restoring, it took a while but the cause for weird ignition behaviour was because of two faults, the ignitionkey switch and the "kill" switch both together...

Last thing is the stator, in my actual project I could not understand why , suddently, the generator stopped worning. All seemed OK , then I discovered the stator wiring insulation was completely obliterated INSIDE the case (basically it is crumbling like dust), therefore they were short circuiting.

Worth checking.

IF I WAS you... I would outsource a complete loom and just replace it, it looks to me you have more than one issue...

Does the charge light really only work if the kill sw is on ? ( just seems wrong to me ) , and any how that voltage sensor wire should be moved to the battery +. If there are some poor connections between the batt and the relay the sensor wire will see less voltage than what is actually at the battery........the reg then compensates and the battery then over charged. like if there is a 2v ( lets say batt v is 13.5v for the sake of this story ) drop to the relay that's sensor wire will see 11.5v and the reg will add 2v to get the right V at the sensor wire ..... which then actually puts 15.5v to the batt.
Getting a 2nd hand harness may well lead you further up the path to madness , probly better off fixing the one you have , or at least prove a fault in it . Do do the test of the alt output as Derek sez . That should have been your 1st test as you should start a fault finding mission at the start , not 1/2 way thru