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Discussion Starter · #1 ·
Normal "Uh-oh´s"
- The bike just lost power and the tach needle was going crazy.
- The bike wanted to die when i goosed the throttle.
- The bike regained power when i shut down the lights or kept the throttle neutral
-The bike suddenly didn´t respond to throttle and the tach dropped to zero.

After a call to a buddy (A Long time Ducati owner) he figured it was a few items that could gone wrong.

From most likely to least likely
*The wires between the generator and alternator had burned out in the connector behind the batteryholder.
*The main fuse was burned out
*The alternator/regulator was burned out
*Bad battery, bad bad battery!
*Generator burnout *groan*
*OTHER DC electrical problem (wirebreak, diods out)
*The flywheel had come loose and ripped up the generator.

It turned out it was the top one.
Older SBK´s have a single phase generator


These have TWO yellow wires running from the leftside to the right side of the engine.
First of all, these wires SUCK, they are to thin and fragile to cope with the loads we put on them. Also, they go through a white quick-connect fitting just behind the batterbox on top of the lower coolant reservoir.

THIS is the culprit (mostly). The connctor isn´t waterproof and moisture gets in and together with the current quickly destroys the connection.


Not to worry. Simple cut away the "fried" part, including the connector, and solder the leads together. It doesn´t matter which to which, since both are yellow and AC-current is used.
This was my fix and it´s been holding strong since.

Other things to check if you don´t get a charge
*Put a multimeter on the battery. Reading should be about 12 volts.
-start engine. voltage should be about 12.5 and JUMPY at idle. (it´s taking alot of pulsating current at this point (not AC, just jumpy DC). if it´s stable, your VRR is NOT charging your battery!)

-blip the throttle (quick jerk on gas) and the voltage should peak at about 13-14 volts if the battery is low.

If this doesn´t happen, you need to start with the basics.
-Is my generator working? Check with multimeter/voltmeter on the yellow wires. You should have AC at about 35 volts ~5000 RPM.
-is my regulator/alternator working? (The thingymajig under the battery) Check outgoing black and red wires. Should be 12.5 volts on idle, NEVER above 14.
-is the fuse good? Well duuuh.. LOOK at it. It´s a green or blue 35 or 40 amp fuse just in front of the battery.
- The wiring from the VRR to the battery MAY be damaged. It has happened.
- The wires runnig from the Generator may have a short down the line. Check them out.

Other issues.
*My batterylamp didn´t shine before i lost power! I know. it only works on pre 96 models. I have no idea why.

Quick check
*Every time i ride my duc i check it. At idle the lowbeam seems a little yellow from low voltage. blipping the gas quick on-off makes the lowbeam shine a little brighter = I´ve got a charging generator! :D This works best in a semidark area like a garage or pointing the lowbeam at a shady wall.

I´ve probably made a few mistakes here. Feel free to comment
 

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Discussion Starter · #2 ·
If the battery has a stable reading when idling, your have one of 4 problems.

*The connecting yellow wiring between the generator and rectifier/alternator has a short or have burned off (VERY common! what my write up discusses).
Fix: Solder them together again

*The rectifier/alternator is damaged (Can be checked by placing a voltmeter on the yellow leads from the generator to alternator/rectifier. When idling they sould read atleast 15volts AC and ~35 volts at 4500-5000RPM)
Fix: Buy new rectifier/alternator unit (The piece under the battery)

*The DC side of the wiring from the rectifier/alternator to the battery is damaged/off/shorted. You have a good AC current, but volts are still stable.
Fix: Check all the wires and see if they are damaged. Replace as needed.

*Generator burned out (Can happen but not very common). If you get 0 volts AC from the yellow generator leads.
Fix: Expensive replacement of the generator.


IF the battery volts are jumpy when putting a voltmeter on the batteryterminals, then you probably have a grounding fault. Check the wiring/connectors/fuses. Clean go from there.

//amullo
 

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Discussion Starter · #3 ·
A Quick note..

The fastest "sure" indicator that your charging system is down is a pretty easy one.

Connect a DC volt meter to your battery.
Make a notation of your voltage - Should be about 12.5v or so.

Start the engine

- IF the voltage is exactly the same (12.5v) or slightly below and DOES NOT CHANGE regardless of RPM (rev it slightly to check), then your system is down and your not getting a charge.

- The best indicator of a WORKING charging system is that the voltage goes up when you rev the engine slightly (say 2500RPM). But it should NEVER exceed 14v.

//amullo
 

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A good way to keep your eye on possible charging/regulator issues is to fit a permanent voltmeter;



This way you can see if it's charging under all conditions, you soon get used to the 'numbers' so if they drop (or even increase) you'll realise before it goes 'pop'.

This unit was inexpensive and easy to fit.

:)
 

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97 900 SSCR Charging Comment

Hello - New member here...

Thanks for the advice. Just picked up an ultra low mileage CR for cheap because quote "it needs a new stator". Basically not charging. I was prepared this morning to tear it down to the stator ring.

I didn't get far before finding the problem. Just like the 3-phase bikes, look at the yellow wires from the generator to the regu/rect. In my case these 2 wires were melted together where the factory put a little U-bend in them to zip tie to the frame (right before the white connectors). The bend must have added just enough resistance to start a heating feedback situation. Pulled em apart and she charges just fine. The real fix (of course) is to now go to bigger diameter (lower gauge) wire and real connectors. There really is no excuse for having such small wiring on a power circuit. I know... I will still buy an aftermarket RR to keep ready.

I think next up is a complete check of all the wiring on the bike. Man, and I thought my old Guzzi had sketchy wiring! Cheers.
 

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A good way to keep your eye on possible charging/regulator issues is to fit a permanent voltmeter;



This way you can see if it's charging under all conditions, you soon get used to the 'numbers' so if they drop (or even increase) you'll realise before it goes 'pop'.

This unit was inexpensive and easy to fit.

:)

I got stuck in the middle of nowhere once due to the yellow wires melting right after I bought my bike. When I did the rebuild I replaced all the wiring with a much heavier gauge and heavier insulated wire.

I like the idea of the volt meter, where did you wire it too?
 

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I like the idea of the volt meter, where did you wire it too?
I ran some 2 core cable directly from the battery terminals (but passed the + through a fuse, just in case) that way it's reading the actual voltage at the battery rather than through lots of other wiring/switches etc which may show voltage loss.
 

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Where did you get the cheapo voltmeter?
 

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Is The Un-Regulated Voltage Spec Right?

From the OP's post "-Is my generator working? Check with multimeter/voltmeter on the yellow wires. You should have AC at about 35 volts ~5000 RPM."

My Haynes manual states that the single phase system should produce the following between the two yellow wires:
  • @1500RPM - >=35VAC
  • @3000RPM - >=70VAC
  • @6000RPM - >=140VAC

What's right?
 

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Discussion Starter · #13 ·
I could be wrong.. Go with what Haynes say, they are usually spot on.

//amullo
 

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Ducati 916 - Charging (or not?)

Gents,

This is a great post and sure, I share the same "stranded" experience on my '95 916. Yes its Single Phase alternator setup.

Would appreciate feedback since I'm still worried about getting stranded miles from home.

Here's my progress so far.
1) Replaced Charging fuse - 30A (in front of battery)
2) Replaced Fuel filter. (old one was clogged bad)
3) Replaced previous fuel pump fuse w/ a 5 Amp. (prev 7.5 Amp)
4) Replaced R/R w/ Electrosport unit. (Previous unit had a Bottom Diode failure according to the Diode Test Guide on their website http://www.electrosport.com/technical-resources/library/diagnosis/pdf/diode-testing-guide.pdf)

My local Ducati guru at Nichols (a reputed shop) talked me into leaving the R/R under the battery. I replaced the in-between wires w/ 10-Guage, ran the wires over water bottle/closer to injectors, soldered connections.
5) New stock battery - the std Yuasa - YB16AL-A2.

Here are my voltage readings... DC, measured at battery.
Battery Volts w/ Ignition OFF - 12.7 V (after a few tests)
At Idle - 12.10 V
At 1500 rpms - 12.8 V
At 3000 rpms - 13.1 V
At 4500 rpms - 13.0 V

Does this sound healthy enough? :confused: Would hate to get stranded again!!!!!

Thanks again.
 

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Yellow or Black and Red for Regulator Functionality?

I have a 996 with charging issues. Is it the black and red wires to check for VRR or the yellow three. In one post it says black and red to determine regulator functionality and in another it says yellow.

I have a warranty but the last time I took it to a Ducati dealer for an inspection, by the time I got home there was a pin sized hole in my fuel line (spewing gas under pressure). So now I opt to do simple things my self.

If the battery has a stable reading when idling, your have one of 4 problems.

*The connecting yellow wiring between the generator and rectifier/alternator has a short or have burned off (VERY common! what my write up discusses).
Fix: Solder them together again

*The rectifier/alternator is damaged (Can be checked by placing a voltmeter on the yellow leads from the generator to alternator/rectifier. When idling they sould read atleast 15volts AC and ~35 volts at 4500-5000RPM)
Fix: Buy new rectifier/alternator unit (The piece under the battery)

*The DC side of the wiring from the rectifier/alternator to the battery is damaged/off/shorted. You have a good AC current, but volts are still stable.
Fix: Check all the wires and see if they are damaged. Replace as needed.

*Generator burned out (Can happen but not very common). If you get 0 volts AC from the yellow generator leads.
Fix: Expensive replacement of the generator.


IF the battery volts are jumpy when putting a voltmeter on the batteryterminals, then you probably have a grounding fault. Check the wiring/connectors/fuses. Clean go from there.

//amullo
 

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Discussion Starter · #16 ·
The easiest check is either a Voltmeter or an Ampere meter.

//amullo
 

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k i have a weird one, and i think it s an old problem, my battery goes depleted as is around 11 v after riding for 5 hours straight, without pause, especially when i use lights (night). i always tought it s the battery since the charing system when i start up the bike and verify it seams ok, as in it increasses to 13v at 3000 rpm and upper, etc.

so it seams that the regulator when hot, it stops working? i bought a new one, hope it fixes, btw i tried with 2 batteries, and only happens after very long hours of non stop riding, so a battery lasted me 2 months, other 3, cause i m not riding very much at one time, but it s definitly a problem and it s not the battery since 2 diff brands were used same with the exact same problem.

also yesterday when i fitted the newly recharged batter 12,35 v, and i started it the first time, it droped to 11.8 , then after some revving went up to 12.2 at idle.
 

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thanks for the info guys. just had a slight hicup with my 996. definitely will be following this through to see if it helps to trace the problem.
 
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