Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Dead bike P2

[TopiToo]

Originally Posted by phil_h

Do not run the bike if your meter shows 17V !
You will end up damaging something else, as it sounds like the rectifier part that turns the ac into dc is not working, so the peak voltage will be even higher. Peak current will be proportional to peak voltage, so beware !
Also, if your regulator is faulty, you shouldnt run the bike with the battery disconnected for the same reason.
Set your meter to ac to check this. There should be no ac with a battery connected.
Putting 17V onto a battery could damage it and/or the wiring beyond repair.

Hello phil_h

Thanks for that, I needed to run the bike to get the readings,
but will not be using it until I can get a new regulator.

not too sure how I would do this though "if your regulator is faulty. you shouldn't run the bike with the battery disconnected for the same reason"

If the battery is diconnected I have no power!!

TopiToo

[phil_h]

Sorry mate - I meant do not _rev_ the bike. Any voltage over about 15 is a sign of a fault.
Check you have a damn good earth at your regulator btw, as that could give false readings when you have current flowing - any resistance will give a volt drop !

[TopiToo]

Originally Posted by phil_h

Check you have a damn good earth at your regulator btw, as that could give false readings when you have current flowing - any resistance will give a volt drop !

Hello phil_h

The regulator that has failed is a Electrex RR51, this has never been
earthed to my knowlege over the passed 3yrs, saying that my old Duc regulator had an earth.

attaching an earth now, are you saying would give different readings?

TopiToo

[phil_h]

Many regulators use their chassis mount as an earth point, so they can flow high current easily - which sometimes gives problems if you have the frame sprayed ! So to avoid this many have a dedicated earth wire so its obvious, but its not as good a method. I'll go and have a look at how mine is earthed and offer some more specific advice, but you can trust me, it wont work without some kind of earth

I can second what phil_h is saying. The regulator uses the earth connection as a point of reference, without one it won't know what to do.

My monsters got a dedicated cable to the regulator earth, i can have a look at the 916 tomorrow to see how it's done on mine and let you know.

[TopiToo]

Originally Posted by Shandy

I can second what phil_h is saying. The regulator uses the earth connection as a point of reference, without one it won't know what to do.

My monsters got a dedicated cable to the regulator earth, i can have a look at the 916 tomorrow to see how it's done on mine and let you know.

Hello Shandy

That would be great, a pic of this earth would be good
showing to and where it goes.

regards

TopiToo

[phil_h]

Right, I've been in the garage and taken the fairing off to see whats its all like and get you some pix ... and there is no direct earth bond from the regulator to the chassis. I've got a 98 SPS, and the regulator is fixed to a rubber mounted heatsink.

the yellow wires are the ac in from the alternator, the 2 green wires are the earth connection from the regulator which connect to 2 black wires going to earth somewhere via the loom. This connection is very important at both ends, so clean the connector block if it looks corroded. From the wiring diagrams, earlier models look to have just one earth connection and a red/white charge light wire. 2 red wires then feed the rectified, regulated voltage into the wiring loom.
(in the pic i'm holding my external charger lead out of the way)
The second pic is there to remind us all that there is a stupid metal connector that can cause faulty readings fitted on either end of the battery. The terminal you fix the wires to is just a swaged-fit into the metal plate and can be pulled through if you overtighten the nut trying to get a 'better' connection - which makes it a worse connection. I've welded up the backs of mine.

[Karl]

Steve, hope this helps. Just looked looked at my 916 and taken this pic. I have a earth wire going from the regulator/heatsink bolt to the main harness.

[keefer]

same as Karl
so it wanst the batteries fault then hey ?top kit that

Mine '95 916bp is the same as Karls, wiring heading off into the loom which i assume goes to the battery negative,





I was out in the garage as Karl posted his picture up, wish i never bothered though as i found a few drips of oil coming off the bottom of the engine, ah well thats another thread for another day.

Cheers,

Shandy