No charge , broken stator wire

[docc]

This has come up before, but it's been a while.  For my Sport, it last happened in 2009 and I couldn't save the stator just reattaching the wire. This time, I removed the stator and made the repair on the bench after eleven years/ 45,000 miles/ 72.600 km and it appears to check out. That is, the resistance through the windings, AC output, and DC charge values all check out. (MΩ from yellow wire to ground is suspiciously low.)

The wiring, mounting points, and strain relief are immensely brittle from the heat making the repair more difficult. I suspect my removing the alternator cover to access the nut to position the motor for valve adjustments every 5,000 miles has contributed to the failure.  I simply must be more mindful and less careless about this in the future. Otherwise, when you have your alternator cover off, be certain to inspect these wire connection very carefully every time . . .

 

[4corsa]

Thank you for sharing this!

[Kiwi_Roy]

My VII Sport did the same thing, the wire was so corroded I couldn't re-solder it so I simply replaced it with new yellow wires.

[docc]

7 hours ago, Kiwi_Roy said:

My VII Sport did the same thing, the wire was so corroded I couldn't re-solder it so I simply replaced it with new yellow wires.

Yes, this time I had to to trim the wire off considerably to get it to solder. Not perfect, so I'll be suspicious of it. I did order a replacement from Electrosport that requires a change to spade connectors, but will hold it in reserve  for now. Interesting that their product description says, "We incorporated a much nicer strain relief and also install the best quality lead wires that offer much better chafe and heat resistance than the stock wires." (I did apply epoxy to the solder joints for "strain relief" this time, but the anchor for the broken Zip-tie was also broken off. Sketchy "strain relief.")

What should we make of the specification that resistance through each of the yellow output leads to ground should be "higher than 10 MΩ" and my old stator is about 3 MΩ?

[Kiwi_Roy]

21 minutes ago, docc said:

Yes, this time I had to to trim the wire off considerably to get it to solder. Not perfect, so I'll be suspicious of it. I did order a replacement from Electrosport that requires a change to spade connectors, but will hold it in reserve  for now. Interesting that their product description says, "We incorporated a much nicer strain relief and also install the best quality lead wires that offer much better chafe and heat resistance than the stock wires." (I did apply epoxy to the solder joints for "strain relief" this time, but the anchor for the broken Zip-tie was also broken off. Sketchy "strain relief.")

What should we make of the specification that resistance through each of the yellow output leads to ground should be "higher than 10 MΩ" and my old stator is about 3 MΩ?

They are referring to the insulation resistance 10 MΩ is what you can expect with new wiring but even 0.5 MΩ is perfectly adequate. We don't normally bother with measuring the insulation resistance for 12V wiring but its standard practice for mains wiring its done at a DC Voltage if I recall correctly 1.5 x normal Voltage so it requires a special meter commonly referred to as a Megger, not just a normal multimeter.

If you use new copper wire you will find it solders well to the existing coils.

[docc]

19 minutes ago, Kiwi_Roy said:

They are referring to the insulation resistance 10 MΩ is what you can expect with new wiring but even 0.5 MΩ is perfectly adequate. We don't normally bother with measuring the insulation resistance for 12V wiring but its standard practice for mains wiring its done at a DC Voltage if I recall correctly 1.5 x normal Voltage so it requires a special meter commonly referred to as a Megger, not just a normal multimeter.

If you use new copper wire you will find it solders well to the existing coils.

Thanks, Kiwi_Roy!

I have to admit to being mighty aggravated yesterday with how hard it is to resolder this common failure. And the idea that an otherwise good stator has to be replaced just because the wire breaks . . .

[hammershaug]

A few weeks ago I cut off those yellow, loose bullet connectors to the regulator. Then soldered and crimped the wires properly. @Tomchri told me to also check the stator wires, and I did. They looked ok. Barely touched them. Afraid of breaking the soldering points... Possibly another weak spot to worry about.

As an electrician I fully agree with @Kiwi_Roy The isolation resistance must be at least 1Mohm in households with 230VAC/400VAC. On a bike with a 12V system, 0,5Mohm is _more_ than enough.


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[al_roethlisberger]

Yeah, it's a shame the OEM unit is just barely good enough regarding durability and output.

Not a terrible price... Does the new stator have any increased output? 

https://www.electrosport.com/collections/street-motorcycles-moto-guzzi-2000-v11-sport/products/esg814-stator-ducati-external-type-2-wire-012-2a

 

These are interesting, but more expensive, options as well especially if one is concerned about power consumption/reserve:

https://gtmotocycles.com/collections/electronics/products/eme-stator

https://gtmotocycles.com/collections/electronics/products/eme-h-o-charging-system-upgrade

 

 

[docc]

These “450 watt” units are apparently identical. In the thread about my 2009 stator failure, Greg Field commented on this. I can link that thread later when I get home...

[Kiwi_Roy]

Replacing the wires is dead simple but you might need a 40 Watt iron, one with a pencil bit may not have quite enough heat

A soldering gun would have plenty of heat or something like a Weller thermostatically controlled one, there's certainly no nend to replace the stator just because the wires are shot.

Out of interest here is the stator from my V7 Special 

[docc]

1 hour ago, docc said:

These “450 watt” units are apparently identical. In the thread about my 2009 stator failure, Greg Field commented on this. I can link that thread later when I get home...

Here is the link to Greg Field's comment on the 450 watt unit. He would know, IMO:

 

[hammershaug]

Yeah, it's a shame the OEM unit is just barely good enough regarding durability and output.
[...]
 
These are interesting, but more expensive, options as well especially if one is concerned about power consumption/reserve:
https://gtmotocycles.com/collections/electronics/products/eme-stator
https://gtmotocycles.com/collections/electronics/products/eme-h-o-charging-system-upgrade
 

”Stable 14.2 Voltage production under all load conditions“

Xmas gift to myself.


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[docc]

Seems that is equivalent to the OEM system. Very curious to see if you find it really is any different.

I'm anxious to see how Electrosport has improved the "strain relief" since this appears to be the weak spot.

[R.I.P. Mikko]

In my opinion and experience in the field, anytime I do wiring work on my equipment I use marine grade tinned wire one size up. I have 100ft spools  of of this exact stuff at my shop.

https://www.fisheriessupply.com/marine-electrical-supplies/wiring?N=23064+4294967103+15560&Ne=10183&Nrpp=40&ct=4294967103

@docc have you thought about using a nice dollop of potting epoxy? Something like this?

 https://www.masterbond.com/tds/ep36ao

[docc]

4 hours ago, Mikko said:

In my opinion and experience in the field, anytime I do wiring work on my equipment I use marine grade tinned wire one size up. I have 100ft spools  of of this exact stuff at my shop.

https://www.fisheriessupply.com/marine-electrical-supplies/wiring?N=23064+4294967103+15560&Ne=10183&Nrpp=40&ct=4294967103

@docc have you thought about using a nice dollop of potting epoxy? Something like this?

 https://www.masterbond.com/tds/ep36ao

That looks like the real deal! Pretty sure every V11 stator should have a pair of "nice dollops" on their stator connections . . .