Vll Rosso Corsa died in transit

[RossoBob]

Hi My 2003 Rosso Corsa cut off 30 minutes into a run today. It started missing and then shut down and would not restart. The battery had been fully charged yesterday and it fired up beautifully this morning to start the run. I was trapped in the hills without tools, however someone stopped and helped jump start the bike and they had a multimeter with them. All the fuses were OK and no evidence of shorts etc. With the light disconnected the battery voltage was dropping again quickly, so it appears there was no charge getting back to the battery. Called a Tow Truck and got home 2 hours later - Turned out to be a long end expensive short run! I have gone over a number of the existing postings and it looks like it is a regulator problem more than the alternator? The wiring diagram I have shows a safety diode protecting the ECU - Are there any other diodes / relays linked to the regulator or alternator I can start looking for? The postings have suggested changing the regulator to an Electrex 451 and running a new negative directly to the battery. I have been able to test the alternator when not running and it reads 5 ohms, with Meg ohms to earth on both sides - Not sure what it should indicate, however this appears to be OK? Any comments & suggestions would be appreciated Cheers

[fotoguzzi]

regulators have been known to crap out if not grounded well.. the stock set up uses the mounting bolts in captured nuts for ground, bad idea. but have you checked to make sure everything is plugged in? like the wires under tank, left front. there are some bullet connectors there that can pull apart. on a Tonti bike of mine once the red wire from reg came unplugged and the battery didn't charge, reg was OK>

[Kiwi_Roy]

regulators have been known to crap out if not grounded well.. the stock set up uses the mounting bolts in captured nuts for ground, bad idea. but have you checked to make sure everything is plugged in? like the wires under tank, left front. there are some bullet connectors there that can pull apart. on a Tonti bike of mine once the red wire from reg came unplugged and the battery didn't charge, reg was OK>

 

As Fotoguzzi says grounding is really important, I suggest make a jumper about 8 inches long with a 1/4" lug at each end and run it from the regulator case to a timing cover screw, file the regulator lug first to get a good connection and add a little grease between the case and lug to prevent it corroding.

Several other things to check.

1/ With the key on you should have 12 Volts at the black wire of the Black/White pair, the regulator needs this to work. If you unplug the headlight fuse thinking this will extend your range with no charging you actually make it worse because the black wire comes from the headlight relay, better to remove the bulb or unplug the headlamp at the headstock. Another sign 12V is missing is no tacho or idiot lights.

2/ The 2 red wires from the regulator combine and feed the battery through a 30 Amp fuse, the socket for this fuse has a habit of developing a high resistance often melting the plastic, easy fixed with a bit of sandpaper and bending the clips to apply more tension

Unplug the two red wires, with your Ohmeter you will get zero Ohms between the socket and Battery Positive

3/ If my bike is anything to go by the yellow wires break off where they are soldered to the alternator coils, you can check for this with an Ohmeter, between the two yellows should read less than an Ohm. If you have a break it may be easier to replace both wires as the copper is probably oxidized. Another easy fix if you have a soldering gun, pencil types don't have enough heat.

 

If you don't want to carry a multimeter as part of your toolkit I suggest carying a 12 Volt LED with about 3 feet leads with this you can get a good idea of Voltage, mark one lead chassis, LEDs are polarity sensitive.

 

Moto Guzzi

Making electricians out of riders for 90 years

[Ritratto98]

Moto Guzzi

Making electricians out of riders for 90 years

 

I love that!!!

[RossoBob]

Thanks for all the help. The problem appears to be both the regulator and a molten connector, however it is a chicken & egg scenario and there is no idea which took the other out first. If this is useful for anyone else: 1. The readings from the alternator @ 3000 - 4000 RPM were 80 - 90VAC when disconnected from the regulator. 2. Be careful with the regulator - At one stage a supplier tried to convince me my alternator was 3 phase, however it is clear from the diagram and 2 cables that it is only single phase. Found a good supplier in Australia who knew the genuine 2003 V11 was the same Japanese regulator used by Ducati. 3. I tried to find a manual for a 2003 V11, however the only copy I could find is in Italian. I will attach this in the forum in another section if it is useful for anyone. If anyone knows where a version in English is available please let me know. Cheers.

[fotoguzzi]

get manuals here,

 

http://thisoldtractor.com/gtbender/moto_guzzi_misc.htm#gtb_workshop_manuals___shop_manuals___service_manuals

[docc]

If anyone knows where a version in English is available please let me know. Cheers.

And you mean "English" in the very broadest sense of the term?

 

(Of course, there is British English, American English, Australian English, Canadian English, New Zealand English, and the kind of "English" you get when Italian manuals are *translated*)

[Kiwi_Roy]

I have a version that I stripped most of the non English text out of. It's quite a large file but prints out on about half a tree.

 

Send me a PM with your e=mail address i will attempt to send it to you.

 

Roy