Electrical Diagnosis!Please Help!

[DMonster1]

So I have a 2002 M750Sie. 4500 miles.Only mechanical upgrades done,none on electrical except for the kickstand bypass.First few months with the bike was great,no problems. Recently Ive been experiencing alot of annoying electrical starting problems so I was hoping that some of you in the know can please help me out.

Usually I can start the engine 99/100times with no indication that anything is wrong.That one time it wont start Ill wait 30secs, say a prayer and try again and it would fire normally,I did that for ahwhile until it just wouldnt start at all "sometimes".When the problem started to arise I figured it was that my battery which was almost 10 years old had taken its last charge and I needed a new one.

I bought a brand new battery and a tender to charge it when not in use.Problem solved right?

The next day I installed a fully charged batt. and she started up like a champ.I was still very leery about going to far from home so I went to fill up gas,no prob.I went to 7-11 grab some cigs,no prob.Stopped in a parking lot,no prob.Went home, parked it for 8 hrs;went out for a night ride,no problem....

So I figured that the problem was solved and decided to go for a long ride to a friends house the following day.We rode together all day,started and stopped my bike atleast 10times.Finally we got to his house,I parked it in the driveway for 5hrs,and guess what happened.(I always make sure that the key was not in "P",I already made that mistake before and dont plan on ever doing that again.")

WE'VE GOT PROBLEMS!"click click click"
I have bright lights,starter clicking,fuel pump priming,nothing seems out of the ordinary besides the CLICK CLICK CLICK....and a big cold hearted beautiful bike that dosent run.

This is now the 2nd time this has happend in the 2weeks after replacing the battery and going on long rides.Im going to buy a Mulitmeter so I can try to diagnose the problem this Sunday.

Does anyone have any procedural tips for me?Or does this sound familiar to anyone?Ive never done anything like this before.

My plans for the weekend include.
-checking and cleaning all connections with automobile M.A.F. cleaner(i dont know what else to use WD-40?) and a brass wire brush.
-I think its called a Leak down test?Basically check for shorts or excessive load on wires with a multimeter.

Maybe its just the "good ol' Ducati charm" that I hear owners talk about?Help me out..any and all suggestions are appreciated..

Thankyou

[Capo]

Make sure you check the following are clean and tight:
The battery terminals
The ground connection to the engine
Both terminals on the solenoid
The starter connection
Brass brush will be fine, a contact cleaner will also help. I coat these connections with corrosion block (A Lear product) but vaseline will work just as well.

[DMonster1]

Cool thanks for the input.I will check all those connections first, and then start testing random conncectors if I cant find anything.Also I'll pick up some of that corrosion block and put everything back together with it applied.


Is there a special type of multimeter I need? (I was just gonna buy the best one I can for $50.00?)
And should all connections look like a brand new penny or can I just give them a quick brush(Ive read sandpaper works also?) and move on?

Sorry Im a electrical noob....

[Capo]

A cheap one will suffice.
I would not think you can test every connection with a meter rather I would pull them clean and protect. A visual inspection will determine the ammount of cleaning required. In most cases contact cleaner would be sufficient.

However in addition to the connections already mentioned I would look at the charging circuit. There is a large connector that joins the regulator to the alternator, it is barely adequate for the power flowing through it and it is not uncommon for them to melt.
While your at it you can measure the alternator output (AC phase to phase) with your newly acquired multimeter.

The following may be of use to you

Charging System.

The following is derived from the charging system as fitted to a S4R, it may be applicable to other models/

Electrical power is generated by a 3 phase 520W (43A) permanent magnet alternator driven directly at engine speed from the left hand end of the crank shaft. The magnetic rotor is bolted to the flywheel and round outside the stator which is fixed to the left hand engine cover (the alternator cover). The alternating current voltage output is proportional to engine speed producing a regulated DC output of 14.5V at 3000 RPM. The frequency of the alternating current also varies with the engine speed,
The maximum system load is well within the capacity of the alternator, up to 28A being available for battery charging at normal loads.

Engine RPM 2000 6000
Output Voltage (Phase/Phase) 27±10 78 ±10

Alternating Current (AC) is rectified to Direct Current (DC) and regulated according to the battery voltage,
AC flows alternately in one direction then the other in cycles that are dependant on the speed of the alternator rotor but typically could be hundreds of times per second. Diodes rectify the AC into DC, which flows in only one direction. Three pairs of diodes rectify both directions of the AC output of each phase.
The regulator' reduces the average current through the rectifier to the amount that is necessary to satisfy the operating loads at any given time, the regulator senses the battery voltage and regulates the output voltage to 14.5Vdc by shorting the alternator phase outputs to ground, limiting the power input to the rectifier. A 40A fuse is fitted in series with the regulator DC output to the battery. Ducati specs the output at 14.5V @ 3000 RPM. When the load is in excess of the alternator output, the battery is discharging to maintain the load.
The ground in the charging system is the negative output from the rectifier. The AC-part of the three phase system is floating from ground, measurement of the AC-output should be from phase to phase, and not from one phase to ground..
In this system, the alternator is producing full power all of the time, the excess power is converted to heat which is dissipated by a finned heat sink surrounding the Rectifier/Regulator (RR).

Charging System Schematic.




System Loads.

Max Actual
Alternator Output Amps 43 43
Alternator Output Watts 520 520
Headlight Main Beam 60 55
Side Light 5 5
Number Plate 5 5
Rear Lamp 5 5
Brake Lamp 21 0
Indicators (2) 20 0
Instrument Panel Lamp 2 2
Fuel Pump 60 60
ECU 48 48
Fans 60 0
Horn 60 0
Total Watts 346 180
Total Amps 29 15
Battery Charge Watts 174 340
Battery Charge Amps 15 28


Operational Issues.

Heat is main cause of RR failures, as noted the alternator produces full power at all times, excess power being shorted to ground, with a fully charged battery over 330W of excess power is converted into heat, additional heat is generated from the rectifier. A flow of cool air over the RR heat sink is essential if problems are to be avoided.

Loose and corroded connections are another source of failures, with up to 40A flowing through the alternator wires, high resistance connections will heat up and have been known to melt the insulation on the wires. All connections should be periodically checked to ensure they are clean and secure. A coating of Corrosion Block Grease (A Lear product) is recommended.

Extensive city use where engine speeds are lower than 3K, will cause the battery to discharge, in such cases the battery should be charged overnight to ensure adequate power availability.

It is recommended that a battery tender be used to maintain the battery charge during periods of no use

[DMonster1]

Thankyou Capo for all your help and quick replies.Very much appreciated.

That is a great 101 on the ducati charging system.I feel like I have a much better level of understanding and a bit more confidence now.Well see how it goes when I roll up the sleeves and get into it.haha

(Is $50.00 considered a cheap multimeter?or should I buy one for like $15-$20?)Ive seen them go for over $200.00 so I thought $50 was cheap enough.....

[DMonster1]

OK so far this is what I have done.I followed the electrosport fault finding guide.

I Fully Charged the battery =13.1V voltage checked after sitting disconnected for 48hrs.

After initial start and engine @2500rpm across the battery terminals 12.8V.

Checked the connection on the positive terminal to the red wire@R/R with engine idling at 1100rpm
0.3V.

I stopped the engine, cleaned and inspected most of all connections with MAF cleaner.I didnt find much,a few loose connections,a few grimey ones,and one spot in a wiring loom that is chafing against the lower triple but is still insulated(visibly signs of rubbing but no wires exposed)I dont know if this could be the cause.

Re-checked the connection between positive terminal and the R/R.Engine ldling=0.6V-0.7V.

Re-checked voltage over battery terminals @2500-5000rpm 12.8-12.9 all the way up and down.

Tomorrow I will check the Alternator output between the three yellow wires in the block connector at the R/R and re-check connectors and wiring and update.


Thankyou, any suggestions appreciated.

[Capo]

Remember to set your meter to AC as the alternator produces AC

[andrea74mad]

Hello everyone! I just registered this forum and cannot really understand how to send messages etc. I gotta a problem just got my monster 916 s4 2001 out of the garage. I recharged the battery which was totally flat and when I tried to start ..... nothing .... The key code light is flashing while i'm trying to start up and it feel like there not enough power in the battery , but the allarm works so the lights . I'm worried about thi code light flashing . I don't know very much about it and I don't have a user manual because I bought the bike from a private last year ..... Is there anyone who could help me to understand what's happening ? Thanks.

[Capo]

Early S4's have the imobiliser unit mounted on the front of the airbox, check that the connections are clean and secure.
Has the bike run since you purchased it?

[tripod]

Originally Posted by DMonster1

Re-checked voltage over battery terminals @2500-5000rpm 12.8-12.9 all the way up and down.

read above discussion, voltage output over 3,000 rpm should be close to 14v.

Consider replacing VR 12.8-12.9 will not maintain a charge in around town riding.