My electrical gremlings

[dark_bike]

Seems you have exactly the same problem I had. 17-18V at start and all charging gone after a while. In my case I had to replace the voltage regulator.

 

Do you have an generator light on your dashboard? You can easily diagnose the regulator and make sure it's not a wiring problem. There's an L-shaped connector leading from your voltage regulator with two wires. The white one is for your regulator light on your dashboard, the black one is the reference voltage for your regulator. You can open up the connector a bit and measure the voltage between the black wire and your regulator ground. If you find your 14V there, then there's something wrong with your wiring or bad grounding etc... But if you have exactly the same readings as when measuring directly on your battery. In that case you know your wiring is correct and your regulator has gone bad. (as was in my case)

 

I replaced mine with a Ducati Energia one which was a bit cheaper then a rebranded Moto Guzzi regulator (and exactly the same), cleaned up all contacts and removed the extra grounding wire from the voltage regulator and my bike has been running fine since.

 

(Much of this info actually comes from Kiwi_Roy, so thank him instead)

 

I do have a generator light and it can be temperamental. This morning e.g. it didnt come on when turning the key. sometimes it glows when idling at traffic lights. at other times everything is normal.

I cleaned the area around the bolt hole of the regulator and fitted a thick wire straight from the regulator o the negative terminal of the battery, so I doubt whether a better ground is possible.

At night the lights vary in brightness so that doesnt sound promising either.

oh well I think I'll stop worrying and love the bomb..er I mean get a new regulator ;-))

[Night Rider]

*Exactly* the same experience I had, temperamental generator light, fluctuating brightness at night (too high voltage), you named it :-)

 

I do have a generator light and it can be temperamental. This morning e.g. it didnt come on when turning the key. sometimes it glows when idling at traffic lights. at other times everything is normal.

I cleaned the area around the bolt hole of the regulator and fitted a thick wire straight from the regulator o the negative terminal of the battery, so I doubt whether a better ground is possible.

At night the lights vary in brightness so that doesnt sound promising either.

oh well I think I'll stop worrying and love the bomb..er I mean get a new regulator ;-))

 

I think I ordered mine at Stein-Dinse, I shipment is free inside Germany if I'm not mistaken ;-)

[dark_bike]

It is indeed. It'll be here by the end of the week :-) A very efficient lot and you can't beat them on their prices...well rarely.

[Kiwi_Roy]

I have re-read the post trying to get a good feel for the solution.

 

Some additional Info

Charging Circuit Problems.pdf

 

Charging Circuit Problems2.pdf

 

In summary.

If the regulator is working OK you should see about 13.8 Volts between the black reference wire and the regulator case with the engine running.

If the battery is over-charging suspect a Voltage drop between the battery and black reference wire.

If the battery is under-charging suspect a bad ground on the regulator. The ground wire provided is totally inadequate for the high current that flows.

The 30 Amp fuse can also have a bad contact resulting in it heating up and/or melting with under-charging.

 

Of course it can always be a bad regulator

 

The V11 Sport has one of Guzzis beter wiring schemes, the reference doesn't go through the ignition switch as on some other Guzzis.

 

Motto Guzzi - making electricians out of riders for 90 years.

[guzzimeister]

Follow the two yellow leads up from the alternator to under the left front of the fuel tank. The two yellow wires have connectors to the main wiring harness at that point. Those connectors are just simple bullets and they change a tad over time from corrosion or mechanical vibration. My guess is that when they get warm (they do pass a lot of current) they start making poor contact.

 

Like a weather report, there is only a small chance that I'm correct but this is another place to look for a cause of your problem(s).

[emry]

Motto Guzzi - making electricians out of riders for 90 years.

 

Best laugh I've had all day!

[dark_bike]

Is there such a thing as progress?

 

I've fitted a new regulator today. Last night the intrument lights were unusually bright then all of a sudden dimmed. now with the new regulator they are steady. also the rev counter needle has steadied- it was a bit wobbly before. I have yet to see how the charging has improved, but so far, it's two gremlins down.

however, now I have instrument lights that dim in time with the indicator...

I had hoped the new regulator wouldalso improve the rather yellowish headlight, but no such luck.

 

one thing's for sure, there is never a dull moment with a guzzi :-)

[luhbo]

Looks as if you have a serious ground problem.

 

Hubert

[Night Rider]

Yes, seems to me too.

 

I'm not sure how the headlight and instrument panel is grounded to the frame, but I would look in that direction.

 

Looks as if you have a serious ground problem.

 

Hubert

[Kiwi_Roy]

Clean the battery terminals and apply grease.

The sluggish start could also be a bad battery ground, check where it connects to the frame, behind the seat

release key on the V11 Sport.

It's not a bad idea to run a good ground from the headlight back to the frame otherwise the current may be

passing thru the steering bearing which is not good.

 

Measure from battery negative to a point on the engine, you should never see any significant voltage either

cranking or with other loads.

[dark_bike]

Ever since I had the bike the headlight was dim. I fitted an Eastrn beaver relay loom in the hope that this would cure the dim headlight but it didnt. Today I took the headlight apart and startet experimenting. I noticed that with dipped beam both filaments glowed (...). not as it should be so I swapped the connectors around a bit till 1 filament lit at each position. problem solved :-)

only question is when those wires were swapped in the first place...

 

the dithery instrument light occurred after I changed the speedo. will have a closer look.

also removed and refitted the earth wire to the engine. all looked ok, but I sanded everything down anyway. Hopefully that does the trick. And sprayed every electrical connection with vaseline.