bike acting funny (battery/charging problem)

[Capo]

The first thing I would do is dissconnect the headlight plug and check the system, again. I am suspecting an overload on the system if your yellow wires are brownish. This means that the system has far too much amperage draw and you are running the rick of melting connectors, wiring insulation, and possibly starting a fire. Now, if the voltage regulator is not out-putting a correct voltage for charging, you need to check the stator...

The alternator is not regulated and outputs full power all the time, the regulator shunts the excess to ground.

The solution as you have indicated is a logical & methodical examination of the system to identify the problem.

The OP may find this helpful http://ducatimonsterforum.org/index.php?topic=14261.0

[Fruity]

thanks everyone for the input. i've used your tutorial capo and i do have a workshop manual. and i've also followed your link howie and did the step by step diagnosis. i pulled out all the fuses and put them back in one by one to check for any draw but none. when i did the tests all faults point to the rectifier (by the way the rectifier is about 5 years old). so i disconnected the rectifier from the bike but left the battery intact on the bike. it's ok now, the voltage hasn't drop at all. previously it would drain the battery dry with the rectifier there. so i'm pretty sure it's the rectifier but i can't be too careful can i quite tempted tho to do as you suggested duke demon. thanks

[Capo]

Looks like it's the regulator.
Chris Kelly is your man.

[Fruity]

capo my man, is there supposed to be a ground wire coming out of the RR? if not is it advisable to ground it? how to? cheers.

[ducpainter]

capo my man, is there supposed to be a ground wire coming out of the RR? if not is it advisable to ground it? how to? cheers.

On my bike the ground is attached out of the harness at one of the RR mounting points.

[Capo]

The regulator is 'grounded' via (in case of the pic), the green pair of wires. I don't recollect a ground connection to the RR mounting bolts.

From what I have read so far, it looks as tho a couple of rectifier diodes have failed enabling a circuit between the positive and negative sides of the battery, the current flowing thru this circuit, was evidenced by the spark you observed when disconnecting the negative battery terminal.

Not much you can do about this other than replacing the RR. But do make sure you burnish, clean and protect from corrosionall the connections.

I'm intruiged as to the cause of the RR failure, it is highly improbable that two diodes on the same circuit 'just failed' at the same time.

Were you having problems before the new battery?
What was the reason for the new battery?
Have you ever jump started the bike?
Have you ever disconnected the battery with the engine running?

[ducpainter]

My bike is carbed.

Maybe that is the difference?

[Fruity]

you're absolutely right capo. when i checked the regulator via the step by step method provided by howie it showed both + and - of the regulator failed. i haven't done anything out of the ordinary. tracing back step by step:-
i) i changed the battery about a year ago coz the stock battery was old (4 years)
ii) later i had an immobilizer problem when i tried to fix the damper but that was sorted out
iii) a year later the "new" battery died. took it to nearest car mechanic to have it charged up (didn't know better then) and that was the start of the series of problems. since then the battery won't hold a charge. got it diagnosed battery was cooked.
iv) got another NEW battery, hooked it up rode the bike, next day battery kaput again.
v) then i started doubting it was the battery's fault
vi) a friend advised me on a way to test the regulator was to unplug the battery whilst the bike was running (i only did it once), he said if the regulator was ok the bike will keep on running. ( i didn't know better)
vii) then i got the multimeter and started doing a whole bunch of test and found out it was the RR indeed.

that's in a nutshell. 

[Capo]

Good that you have now resolved your problem.
I note that there were only 2 replies to this question on TOB.

[Fruity]

TOB, is that "the old battery"? anyway, pictures say a thousand words.







i was wondering if the wire discoloration was due to old age or excessive heat? coz the part where its under the plastic cover (which i have cut in these pictures) looks fine. hmmm...what do you guys think

[erkishhorde]

When my voltage regulator died on '95 m900 it cooked more than half of the wires that come out of it and the burning/ melting insulation caused the bike to look like it was on fire.  The couple wires that weren't burnt through were kinda brittle and after flexing them a few times they broke from fatigue like when you bend a paper clip too many times.

Mine happened to die on me after I slowed down due to traffic (couldn't split since my parents were following me in a car w/ all my stuff). It was almost like the air blowing on the regulator was the only thing keeping it going and once I slowed down it cooked itself in less than 5 minutes. I don't know a whole lot about how it works but I'd say that the discoloration of the insulation is a sign of heat due to resistance and the resistance is probably a sign of the broken regulator.

Side note, how did you knick up that middle right fin by the bolt hole so bad?

Oh, and ToB is "the old board" referring to the ducatimonsterlist that we all left in favor of here. Long story, but if you search around a bit I'm sure you can find the story.

[Fruity]

ah!!! comprende. "the old board" ya, bummer.

the knick on the fin was already there when i bought the bike. so i have no idea. 

[Howie]

Usually the heat discoloration comes from high resistance at the stator connection and the high resistance is the cause of the regulator death.  Do carefully check that connector for signs of heat damage and that the connection is clean and tight and repair as necessary.  Some dielectric grease in the connector will keep the elements out.

[Langanobob]

I note that there were only 2 replies to this question on TOB.

To go off topic for a moment: It seems to me that this board has reached a point where it's not only better than TOB, it's better than TOB ever was, even before the sale.   The threads in general seem to be a lot more positive.  There are a couple of good guys that don't seem to have made the transfer here, Ducman 851 being one of them and they are missed, but there are also a few jackasses that have never shown up here so I think it's a  net gain.

I was trying to keep this a positive post and my apologies for referring to any fellow Monster riders as jackasses.

Back on topic, I haven't had any rr issues yet, but thanks to this thread I think I will move it more into the air stream.

[Capo]

To go off topic for a moment: It seems to me that this board has reached a point where it's not only better than TOB, it's better than TOB ever was, even before the sale.   The threads in general seem to be a lot more positive.  There are a couple of good guys that don't seem to have made the transfer here, Ducman 851 being one of them and they are missed, but there are also a few jackasses that have never shown up here so I think it's a  net gain.

I was trying to keep this a positive post and my apologies for referring to any fellow Monster riders as jackasses.

Back on topic, I haven't had any rr issues yet, but thanks to this thread I think I will move it more into the air stream.

I hope you pushed the button 

http://ducatimonsterforum.org/index.php?topic=16446.0