Where is it possible to place the voltage regulator?

lceriani · Post by **lceriani** » Wed Jul 06, 2005 5:05 pm

Hallo,
I just suffered the usual, annoying voltage regulator failure with the consequent fried battery. I already used a new unit from Ducati Energia (M900/916 non-original replacement, 130€, with adapted wiring) and I already did some circuit modifications (basically doubling the ground connections), but it was not sufficient to avoid the incident.
I begin to think that the problem is a poor air ventilation over the regulator that causes overheating. So I wonder if is it possible to place the regulator in a different position, for example on the side of the frame, like on some 907 (ie http://www.geocities.com/pbp2go/ducati/ ... lator2.jpg)
Does anyone have experience about this?

LC

Post by **jcslocum** » Thu Jul 07, 2005 7:36 pm

Have you made the relay change to the wiring yet??

The poor connections create the problem you describe by telling the regulator that the voltage is low. The regulator then overcharges the battery and burns itself out in the process.

redpaso · Post by **redpaso** » Thu Jul 07, 2005 11:58 pm

Are the wiring mods that you speak of also applicable for the 906?

lceriani · Post by **lceriani** » Sat Jul 09, 2005 7:53 pm

I didn't apply the relay mod yet.
Indeed I measured that the "input voltage reference" line to the regulator is about 9V with engine running and lights on, so I suppose it's the cause of malfuncion: 3V are lost in the circuit and the regulator always is set to overcharge the battery...!
I thought to re-cable all the lines with 1,5 sqare mm cable but... are you sure that the relay mod is sufficient?

LC

lceriani · Post by **lceriani** » Sat Jul 09, 2005 11:08 pm

I found something that I don't understand, I hope someone can help me.
According to schematics, Paso generator has 3 wires (green-green-red) and they go to the 3 plugs of the voltage regulator labelled as G-G-R. Is the red wire connected (or shorted) also to the red and pink cables that exit frome the rectifier on plug labelled B?
If yes, it means that one wire of the generator is connected to the positive (+) pole of the battery?
(I found my schematics not well readable about this)

Thanks,

LC

Post by **jcslocum** » Sun Jul 10, 2005 11:22 am

lceriani wrote:I didn't apply the relay mod yet.
Indeed I measured that the "input voltage reference" line to the regulator is about 9V with engine running and lights on, so I suppose it's the cause of malfuncion: 3V are lost in the circuit and the regulator always is set to overcharge the battery...!
I thought to re-cable all the lines with 1,5 sqare mm cable but... are you sure that the relay mod is sufficient?

LC

You need to rev the engine to about 3000 to get a good measure of the voltage but yoou result is like what my Paso had before the relays. The connectors and the amount of wire is ridiculous. The relay mod keeps the wiring to about 1 foot, all under the seat. The rest of the witing is just used to switch the relay so it has no effect on the voltage or regulator.

Post by **jcslocum** » Sun Jul 10, 2005 11:25 am

redpaso wrote:Are the wiring mods that you speak of also applicable for the 906?

Does the 906 suffer from the same crap wiring as the 750? I'm not familiar with the wiring diagram.

Gwenadu · Post by **Gwenadu** » Sun Jul 10, 2005 10:55 pm

redpaso wrote:Are the wiring mods that you speak of also applicable for the 906?

My 88 750 Paso have the same Marelli ignition system than the 906, and the same wire colours for this part ( I have compared the two wirings on the "Revue MOTO Technique" [www.etai.fr] before I installed the relays). Wait a few days, I will remove the fairings and make a little diagram of my modifications, I am too busy these days...
Alain.

lceriani · Post by **lceriani** » Mon Jul 11, 2005 7:42 am

I discoved that the wire that bring the voltage reference to the regulator is the green/black one and it is connected to the regulator AFTER a long trip along many electrical loads, so it set the voltage reference to a value that can be quite lower than the real battery voltage.

Yesterday I try a new mod: I connected the voltage regulator reference wire to the orange wire that exits frome the fuse box and is not connected to anything (at least in my bike, maybe it is for auxiliary circuits). The orange wire is on a fused line in parallel to the green/black line, so it should have the same voltage, but having less loads connected, it should be more stable.

I also relocated the voltage regulator unit to the left side of the bike (I hope it will benefit from a better air flow) and I crimped new connectors. I was about to apply the main relay mod that -I discovered- is already applied on Ducati monster. I stopped only for a pair of doubt, that I'll explain when I'll have more info.

However one thing is still missing: the red wire that comes frome the generator (with the other 2 yellow wires) shoud be connected to positive pole or not?

Please help!

LC

Post by **Skins** » Mon Jul 11, 2005 7:56 am

Luca, in my Workshop Manual wiring diagram, there are two red wires coming from the + battery terminal. One goes to the solenoid, the other to the fuses.

Post by **Skins** » Mon Jul 11, 2005 8:00 am

From the solenoid, the red wire becomes red and black and goes to the regulator terminal which has a pink wire on it also.

Post by **Skins** » Mon Jul 11, 2005 8:03 am

It looks like the red wire from the alternator goes only to the regulator, not to the battery.

PS: I've just checked on the bike, and it is as I've described above.

lceriani · Post by **lceriani** » Mon Jul 11, 2005 8:45 am

Ok, thanks!
My copy of the manual wasn't clear about this.

LC

lceriani · Post by **lceriani** » Tue Jul 12, 2005 10:28 am

I had confirmation about my doubts on the relay mod, but since this topic is about voltage regulator relocation, I'll move to "750 Paso Wiring Upgrade to Improve Starting" by jcslocum...

LC

Rodney · Post by **Rodney** » Thu Jul 14, 2005 6:53 am

:ugh: the voltage regulator is on the plate under the seat because
they use it as a heatsink for the cooling of it also i think it uses the
case as an earth . but you can only try the new position to see if
it works

Rodney