S4 Voltage Problem (EOBC Engine Block Light Again)

[mintyhit]

Morning all… So I am completed flummoxed by this problem:

Basically I’ve had the engine block warning light (EOBC) intermittently coming on for ages now (see my other posts). Some weeks it is on almost all the time, others it is more random.

In addition to the engine light problem my battery randomly goes flat, as in, fine for weeks and then bam, leaves me stranded. At first I thought it a dodgy battery but I bought a new one recently and I have the same problem. It will start perfectly everyday for two weeks then *click* barely enough juice to turn the engine over.

So I’ve been slowly changing sensors and cleaning connections in an attempt to fix the issue but to no avail then last night I made an interesting discovery:

For a change the engine light was still on when I pulled up on my drive so I decided to hook up the multi-meter again to check the charging circuit… this is what I got:

1000rpm – 8v – 9v
3000rpm – 10 – 11v
5000rpm – 8v – 17v – very erratic

Strangely enough I killed the engine, let it sit for a while, restarted and got:

Off – 12.7v
1000rpm – 13.5v
2000rpm – 14.1v
5000rpm – 14.5v

This was with the EDOC light off.

I also tested the 3 yellow wires connecting the generator the regulator but I couldn’t get a voltage across any of them on my multi-meter. This is baffling considering the generator would seem to be working?

I guess a dodgy charging circuit would also explain why my battery goes flat every now and again but I am not sure what to change next... does anyone have any ideas?

Cheers everyone
James

[Gerry]

Hi ... did u set your multimeter to AC when you checked the phases on the alternator.

If these are ok then it would look like a regulator to me. I'm sure ive read somewhere that the connector from the alternator to the reg can go intermittant on the ducs .... anyone had this?

[mintyhit]

Ah... no I still had it on DC.

Ok, i've just been down to retest and I got:

1000rpm - 10.9
2000rpm - 7.8
3000rpm - 8.5

Not looking good is it? :(

[mintyhit]

Scratch that... I was doing it wrong... needed to unplug the connector.

Ok so we have:

2000rpm - 25
4000rpm - 42
6000rpm - 69 (Setting off 2 nearby car alarms)

So my generator is fine... phew.

[Gerry]

Sorry ... I'm at work ....ha ha .... yeah that sounds ok ... after checking connectors etc I'd think it was the reg .....

[mintyhit]

Haha, me too!

I am conducting all these experiments in the underground car park of a government office. I keep expecting to get told off for revving my engine. :)

Yeah I agree, I’ll have a proper go at cleaning all the contacts in the connector blocks and failing that I’ll just have to bite the bullet and get on of these:

http://www.electrexworld.co.uk/pdfs/Ducati-RR-Info.pdf

Looks like I need the RR53.... £88 :(

[Gerry]

You could do continuity checks from the phases up to the reg across the connectors and wiggle em around ....

[Gerry]

At home ...

[mintyhit]

Right, cleaned the **** out of all the connectors last, night charged the battery and went out of a spin… 10min in and the familiar sight of that amber engine light greats me once again.

Checked the voltage across the battery again and found it to be spiking between 10 - 19v. So in conclusion… the regulator rectifier is FUBR.

What is it with the Italians and electricity?

[animaluk]

Right, cleaned the **** out of all the connectors last, night charged the battery and went out of a spin… 10min in and the familiar sight of that amber engine light greats me once again.

Checked the voltage across the battery again and found it to be spiking between 10 - 19v. So in conclusion… the regulator rectifier is FUBR.

What is it with the Italians and electricity?

most of the R/R are jap made

I just replaced the R/R with the one you are looking at transformed the bike and stopped all the slow turning over and other problems i was having, well worth swapping them out

I only thought about it after the faulty one cooked off my batt :(

[Gerry]

Now you would think they would be masters .... what with Volta, Ferranti, Marconi ....etc etc ......

Looks like as it gets warm it starts to breakdown ......

[animaluk]

Now you would think they would be masters .... what with Volta, Ferranti, Marconi ....etc etc ......

Looks like as it gets warm it starts to breakdown ......

And ducati itself being born out of and electronics company

[analogue_rogue]

that reg.. im sure there was another make that was cheaper..? (i might have made that up)

[utopia]

I think that other company might be Wemoto. I think I need one too, same type (for 3 phase alternator), but even though they claim to stock the right one, the pics on their website seem to all show another type with different wiring, which looks more like its for the single phase alt. Might be worth a phone call though?

[analogue_rogue]

definately worth a phone call.. this must be a generic system used on a few bike.. as long as voltages and currents etc are right it can be made to fit surely?

[mintyhit]

I might give em a call today... perhaps a club discount can be arranged?

Sounds like this part has a pretty high fail rating.

[mintyhit]

Woo, I changed it!

I was feeling a bit poor this month though so I had to settle for another Ducati one from a scrap yard, I think it was from a super sport and cost me £30.

Anyway, 30 seconds to change and what a difference it has made. It feels like a new bike in comparison. Its funny how gradual degradation over a few months caused me not to really notice the incredibly poor running (probably due to weak spark) and starting.

Anyway, I am expecting this Ducati one to fail again soon but at least I know what to look out for now.

Cheers
James

[Gerry]

Result !

All adds to your knowledge ...