Alternator/(generator?) not charging

[Rox Lemans]

Normally it's just a voltage regulator. Plug and go. 

But with both of mine regardless I'll get 2 years on a battery between the battery starting a high compression motor, the heat of Arizona sapping the battery and the Luigi (Lucus's Italian cousin) electrics. 

My Triumph Bonnevilles were the same way. 

And mind you these bikes are 20 years old now. Vibrations rattling solder points, etc.  

My Scura needs a battery after 2 years. Got exactly 2 years, 2 weeks out of the Yuasa. 

[Weegie]

Dunno if this will be any use, but I stumbled across a thread on WG about a similar issue with a Cali

Pretty certain it's the same system and in there is a schematic from Roy with suggestions on how to test said Reg/Rec (but you'd need a scope).

Useful thing to "squirrel" away, even if it's just to take to an Auto Electrician if you were going to ask him to take a look at the Reg/Rec

https://wildguzzi.com/forum/index.php?topic=111896.0

 

7 hours ago, Rox Lemans said:

Normally it's just a voltage regulator. Plug and go. 

But with both of mine regardless I'll get 2 years on a battery between the battery starting a high compression motor, the heat of Arizona sapping the battery and the Luigi (Lucus's Italian cousin) electrics. 

My Triumph Bonnevilles were the same way. 

And mind you these bikes are 20 years old now. Vibrations rattling solder points, etc.  

My Scura needs a battery after 2 years. Got exactly 2 years, 2 weeks out of the Yuasa. 

Ouch 2 years out a battery, guess that's the price you pay living somewhere you get good weather and can ride a bit.

I'll get 8 years at least out a battery like an Odessey, but with the weather here in Jockland most of the time the bikes are simply sheltering from the rain.

Been a long time since I rode owned a Triumph, but their charging systems were even worse. Seem to recall that massive Zener with all the cooling fins sticking out the triple tree. More than one ocassion I was left trying to make it somewhere in the dark on the side/parking light when both filaments blew in the H4? thanks to Uncle Joe. I was young in those days and had other things on my mind. A dodgy headlight wasn't going to get in the way of a night with the g/f (how times change).

Not knocking older Triumph's though, they were/are great bikes, Bonnies and Tigers especially, simple and super fun.

John

[Kiwi_Roy]

John asked me to look in on this thread, I used to know quite a bit about these systems.

Firstly the alternator wires can be a problem, they snap off where they solder to the coils. When this happened to mine the copper was so corroded it was not possible to re-solder them so time for some new wires, its quite easy to solder the new copper to the coils. 

The bullet connectors where the regulator plugs into the stator leads often overheat, if this is a problem just chop the bullet connectors off and join to the alternator with crimp links or a solder joint.

Grounding the regulator is critical, all the charging current travels back from the chassis to the regulator case so it can return to the alternator through the other yellow wire. The factory supply a small black wire from the case all the way to battery negative but this is far too small for the current involved. Run a short wire from the regulator case to a timing cover screw, the engine and battery main ground are massive compared to the tiny black wire.

The regulator has a rectifier set up as a bridge, 2 diodes and 2 Silicon Controlled Rectifiers. The rectifiers sometimes go open circuit, this situation is very easy to set for if you have a meter with the diode test function, The diodes are connected from each yellow wire to the red wire, it should show about 0.5 Volt, since the diodes are between each yellow wire and the red pair its possible to add a diode on the outside.

The way they measure the battery Voltage is very poor, it taps off the feed to the headlight after the headlight relay and in some cases a normally closed contact of the start relay. The relay contact and socket resistance changes with time, the Voltage drop can be anything from 0.6 to 1 Volt, I have a theory that the reference voltage drop approaches 1 Voltmeaning the battery Voltage has to be pushed above 15 to supply the regulator reference, this high Voltage demands more current which overheats the diodes unit the leads melt off.

 A warning sign can be the headlight out or the tachometer not working, chances are the battery is not charging and of course the charge light also fed from the headlight relay won't be working either fooling you into thinking everything is ok. I often thought of getting the Voltage reference from a different source downstream of the ignition switch,  off one of the ECU relays or from a dedicated relay direct from the battery. This would give the regulator a lower Voltage reference because it expects a drop through the relay but it could easily be compensated for with some resistance ora diode in series.

I struggled with this flakey Voltage reference for years then I upgraded to a permanently connected regulator from Electrosport, there was one minor drawback a parasitic drain on the battery, I used to disconnect the regulator over the winter but if you don't remember to re-connect it next thing you know the bike dies with a flat battery.

Electrosport recommend their ESR515, I dont agree, it still relies on the flakey Voltage reference  and a good ground connection. I used the ESR510 it is wired direct to the battery and it has a dedicated ground wire I don't think it supports the charge light.

Instead of a charge light I recommend just purchase a battery Voltmeter for ~ $15 and hook it downstream of the ignition switch this will leave you in no doubt. https://www.amazon.com/12V-Voltmeter-Color-Digital-Display/dp/B07HHTZ1L5/ref=sr_1_46?dchild=1&keywords=12+volt+battery+meter&qid=1633586264&sr=8-46

 

[Purloined]

Wow, Kiwi_Roy, exhaustive. 

I replaced the regulator after navigating through the V11lemans Tutorial Committee's advice and my bike is on the road and only needed human power for propulsion once since, a few days ago, when I ran it out of fuel. It has trained me well in the art pushing it around. I'm beginning to believe it learned a few tricks in an S & M dungeon and I'm its rube.  

I discovered a fried black wire in the harness under the seat a while back and appealed to the collective wisdom implicit here and ran a more robust wire from the regulator to ground. The electrical system seemed good enough to earn a grade of D, graded on a curve, in a class filled with Moto Guzzi addicts; until the regulator quit, was replaced and here I am still crying into my beer to anyone who'll listen. But it runs, only if I give it a drink of gasoline, but it is running. 

Almost overwhelming, the well written detail in your post. I do have a battery drain, it would be nice if I could vanquish it. I will cajole a friend who's education exceeds my kindergarten diploma in electrical/electronic summer camp to read over my shoulder and parse what you're recommending. He'll sketch a few illustrations in cartoon form and I'll get it. 

 Thank you.

[footgoose]

39 minutes ago, Purloined said:

Wow, Kiwi_Roy, exhaustive. 

I replaced the regulator after navigating through the V11lemans Tutorial Committee's advice and my bike is on the road and only needed human power for propulsion once since, a few days ago, when I ran it out of fuel. It has trained me well in the art pushing it around. I'm beginning to believe it learned a few tricks in an S & M dungeon and I'm its rube.  

I discovered a fried black wire in the harness under the seat a while back and appealed to the collective wisdom implicit here and ran a more robust wire from the regulator to ground. The electrical system seemed good enough to earn a grade of D, graded on a curve, in a class filled with Moto Guzzi addicts; until the regulator quit, was replaced and here I am still crying into my beer to anyone who'll listen. But it runs, only if I give it a drink of gasoline, but it is running. 

Almost overwhelming, the well written detail in your post. I do have a battery drain, it would be nice if I could vanquish it. I will cajole a friend who's education exceeds my kindergarten diploma in electrical/electronic summer camp to read over my shoulder and parse what you're recommending. He'll sketch a few illustrations in cartoon form and I'll get it. 

 Thank you.

I'd like a copy of those cartoons when finished please ...

[Purloined]

14 minutes ago, footgoose said:

I'd like a copy of those cartoons when finished please ...

I'll do my best, but they usually jam the mimeograph machine. They say I should be more careful with my graham crackers and milk. I think they're just lazy and don't want to crank the thing. 

[Kiwi_Roy]

On 10/7/2021 at 9:58 AM, Purloined said:

 

I discovered a fried black wire in the harness under the seat a while back and appealed to the collective wisdom  

 

Probably the ground to the ECU, This will fry pretty quick if you try disconnecting the battery terminals in the wrong order then accidental let your wrench touch the ECU

Always disconnect the negative terminal first, reconnect it last that way there is no return path to fry little wires,

[docc]

15 hours ago, Kiwi_Roy said:

Probably the ground to the ECU, This will fry pretty quick if you try disconnecting the battery terminals in the wrong order then accidental let your wrench touch the ECU

Always disconnect the negative terminal first, reconnect it last that way there is no return path to fry little wires,

And/Or faulty main ground to the back of the gearbox. Don't ask your starter to find am alternate ground path . . .

[Kiwi_Roy]

1 hour ago, docc said:

And/Or faulty main ground to the back of the gearbox. Don't ask your starter to find am alternate ground path . . .

Yes, that's the other one, My VII Sport was grounded to thereat release switch, I noticed it was slow to crank one day but fortunately I figured out what it was before that happened.

[Purloined]

If I go to sleep with a V11 wiring harness under my pillow, or whatever electrical part imparts the most wisdom, will I wake up as all-knowing as you guys in the morning? Is that what you do?

No. I don't think so. I will have awful creases in my cheek and sheets stained from the charcoal-black, burned wires. 

[Mike Stewart]

Just wanted to give a shout out Thank you for this post, needed it to check my charging system on my newly 03 EV with a glowing charge light. I had great AC voltages through the RPMs, so its regulator time. Placed an order through Electro Sport and it's on it's way! 

[4corsa]

Once again the sage advice from this forum has saved me countless hours and probably some $$$. 3 weekends ago while riding my 03 Le Mans home I experienced fading dash lights, followed by a dying tach, and 5 miles later a backfiring engine. Didn't quite make it home.
After checking the fuses, testing the Omrons, and then the alternator (thanks to all contributors in this topic!), it was clear that it was likely the regulator/rectifier. I placed my order with ElectroSport. But here's where I can make a small contribution - the Guzzi OEM regulator/rectifier changed in early 03, and has different connectors and no low voltage warning light (see attached photos from MG Cycle website). I sent these photos to Kyle at ElectroSport and followed up with a call. Their 03 version did not come with these connectors stock, but he was happy to modify it for me, and also tie-off the accessory wires for the warning light. So it was 100% plug and play when it arrived.

I installed it Saturday and after a 90 miles ride my Odyssey battery measured 12.63v - seems all is good. Thanks again to everyone for making this a simple repair!

Sent from my Pixel 4a using Tapatalk

[docc]

FWIW, I would expect my Odyssey to read 12.63v (~85%) after it sat for a week.

After a sustained ride, like 90 miles, charging at 14.2 volts, I would expect it to be over 13 volts slowly falling off to a hopeful 100% (12.84v) after a few hours sitting.

[4corsa]

I'll top off the Odyssey on the charger and see what reading I get, and then keep an eye on it after rides. I don't know if draining it down so low on that fateful ride home had any negative affect on it (no pun intended). I did charge it for 48 hours after I got it home that day.

Sent from my Pixel 4a using Tapatalk

[docc]

I am currently "conditioning" my eleven year old Odyssey PC545 that lives a dogged and neglected life in my CubCadet tractor, swampee, that largely just serves as a test bed for what happens to old PC545s. 

Expecting our G-string rated V11 charging system to bring back a needy Odyssey is probably asking too much of the system. Even my dedicated EnerSys Ultimizer charger wouldn't pull the old PC545 out this time - had to discharge the battery, then manually apply 10 amps until the voltage reached 15v; then attach the Ultimizer for the 13.56v "bulk charge" for 24 hours. Then repeat until the PC545 holds above 12.65 volts for days to weeks.

@4corsa, check your charging voltage with your V11 running. Also, don't expect anything less than a 6 amp charger to actually charge a PC545 (assuming that is the battery you are using).