charging system upgrade for the '81 Vert ???

[dsrdave]

The charging system has been giving me problems off an on for a while so I need to take care of it.  I thought it would be a good time to install one of Greg's harness' and upgrade the alternator.  I'm considering the enduralast 30amp alternator conversion.  Does anyone have experience with it or another suggestion ??  Thx, Dave.

[pehayes]

Please describe the symptoms of "... giving me problems...".
What is the age and technology of your battery?
Converts have a chronic problem because they do not often spin up to higher rpm.  The alternator doesn't have much output at the normal putt around rpm range.  Do you have any extra lights?  Do you run any other electrical accessories?  The basic bike is marginal charging at best.

I have often commented that the best charging upgrade for an Convert is to install a good quality AGM class battery.  AGM have a slightly higher standing voltage than flooded cell batteries.  This causes the alternator to start charging at a lower rpm and to have greater output at all rpm.  I used to always require a bi-weekly boost on an overnight trickle charger.  AGM battery solved all that.  I use the Westco from Euro Moto Electrics:

http://www.euromotoelectrics.com/Battery-R-Airhead-K-Moto-Guzzi-BAT-12V30-p/bat-12v30.htm

Patrick Hayes
Fremont CA

[TOMB]

I'm still running these stock type alternator on my convert one thing I did to improve it was make sure the grounds are good especially from the battery to the frame location and I installed a adjustable voltage regulator now the only lights I have on the bike or whatever came with it that are faring with running lights and I put a set of running lights in the back which are also turn signals so my overall amperage draw is not a lot but with the adjustable voltage regulator and my headlight on high beam I set the voltage regulator to 13 and a half volts easily 8 to 10 years ago never had a problem with a dead battery but they just went through their normal lifespan
TOMB

[TOMB]

Plus the battery is a lawn mower type from Auto zone and is 430 cca With this size battery if I need a battery on the road it can be found at Walmart auto part stores lawn and garden etc
TOMB

[dsrdave]

I use the vert as my tug for the sidecar.  Almost always run in low range.  Full size car battery in the hack.  Led hlp and led's in most of the lamps.  Battery at times just very slowly will get too low on voltage.  Most recently the charge light will not go out.  Rotor resistance measures correct, voltage regulator replaced, diode board replaced and all wiring on the charge system and grounds inspected but may have missed something....

[Kiwi_Roy]

The charge light on is trying to tell us something, that should go out. I suspect the field winding is not energized. Measure the Voltage across the brushes at a high idle.

Rectifier Ground
Something is missing

[pehayes]

Full size car battery in the hack. 

Might be full sized, but what is the standing voltage?  Let it sit over night and measure the voltage at the terminals before turning anything on.  Then, turn on the key and measure the voltage without trying a start.  Report back.

Patrick Hayes
Fremont CA

[chuck peterson]

I use the vert as my tug for the sidecar.  Almost always run in low range.  Full size car battery in the hack.  Led hlp and led's in most of the lamps.  Battery at times just very slowly will get too low on voltage.  Most recently the charge light will not go out.  Rotor resistance measures correct, voltage regulator replaced, diode board replaced and all wiring on the charge system and grounds inspected but may have missed something....

I've seen a brush at the end of its life look as if it was useful...fool me once,...

And then there was the poor solder on one...

The front wiring loom can look good, but very high resistance from being baked for days, weeks, months, 35 years...

And then there is the strange sensation when you think it couldn't be the diode board, because you just replaced it. Walking to look at your notes marketed on the garage wall, oops that was six years and eighty thousand miles ago...

A second ground diode board to motor..

Need a new ground wire from battery to chassis?

[jvb]

I'm considering the enduralast 30amp alternator conversion.  Does anyone have experience with it or another suggestion ??  Thx, Dave.

All nice and sensible but nobody has answered the question!

[Kiwi_Roy]

I have no experience with it but from the brochure it certainly looks good.

I think I would try to find out why the stock one is not working correctly first.

[dsrdave]

Standing voltage at the lead/acid battery is 12.73v drops to 12.47v when the switch is turned on.  Voltage across the brushes is 0.27 At a high idle, approx 1800rpm.

[Kiwi_Roy]

That's way too low across the brushes there's the problem I will have a look at schematic when I get to work.
In the meantime measure the resistance of each of the yellow wires to each other and ground

[Antietam Classic Cycle]

The charging system has been giving me problems off an on for a while so I need to take care of it.  I thought it would be a good time to install one of Greg's harness' and upgrade the alternator.  I'm considering the enduralast 30amp alternator conversion.  Does anyone have experience with it or another suggestion ??  Thx, Dave.

I've installed two of the EDL 450 systems and two of the EDL 400 systems. The former is easier to install and has more output, but is a bit more expensive of course. The latter is nearly as powerful, a bit more complicated to install but still not hard and considerably less expensive. Either one works very well, though the 450 watt set up does seem to have a slightly higher rate of regulator/rectifier failure.

[Kiwi_Roy]

OK I'm back.
The charge light on the dash feeds a little bit of current say 100 milliamps (cannot be an LED without a shunt resistor) to the 61 & D+ terminal of the rectifier which passes it thru to the regulator D+ which passes it through some transistors to the DF terminal which is connected to the alternator brush DF terminal. So at rest if you lift a brush or pull the DF terminal the light should go out.
The Regulator must have a good ground otherwise it cannot turn the transistors On.
This small current is enough to excite the spinning rotor which produces AC Voltage in the stator, this is rectified by the three small diodes and the 3 large grounded ones which raises the voltage at the 61 D+ terminal the Voltage at the regulator and the brushes until eventually you see full battery Voltage on 61 D+
It's very important that the rectifier is well grounded, all the charging current passes through that connection and without it the alternator and the 3 small diodes are not able to boost the 61 D+ terminals.
All the alternators I have seen have one brush grounded however the schematics usually show the D- terminal grounded by a wire to regulator and ground.

One test you can do on the alternator is pull off the DF wire and connect 12 Volts from the battery to that terminal, you should get a healthy spark and hear the motor slow a bit as the alternator puts out full current.
Don't leave it like that of course or you will soon overcharge the battery.
The regulator ground is very important as well it's required to turn the transistors on so the voltage from 51 can be passed to the DF terminal.

[bmc5733946]

The "full fielding" with battery voltage that Roy describes is actually a really good diagnostic tool that can inform about alternator performance capability and was the common method for autos for many decades. Most autos had the rectifier in the alternator and voltage regulation separately, the "full fielding" was used to check for mis-regulation of voltage, usually when there was a lacking of charging. I have used this test on Guzzis for a long time just to check for charging capability. It also seems to cure some problems with brush contact, apparently it cleans the brush to rotor contact. I've actually had it cure some problems permanently, doesn't seem possible but seems to be true.

Brian

[dsrdave]

Testing shows no resistance across yellow wires or to ground from them

[bmc5733946]

That sounds like an open stator! I think you have found your problem.

Brian

[Kiwi_Roy]

Brian,
        I assumed he meant 0 Ohms between the wires and no connection to ground.

Re your comment about full fielding improving an alternator - my Cali II gets a film on the slip-rings that drops the output by 10% or more, clean it off with glass paper and it works better for a while, perhaps application of the battery does the same thing.