maybe its the alternator and a French EOBD program

[cc]

The V6 has developed electrical problems as detailed in previous posts. Which have disappeared or significantly lessened after replacing the battery or recharging it with a CTEK multi xs 4003 charger.

Im hoping to do another Bris Syd Bris trip and also need to attend to the:
leaking front right power steering pipe. (low front radiator supportcrossmember  grounded and bent again!)
Worn (noisy) serpentine belt tensioner wheel. (Not replacing the entire tensioner assembly, just the wheel as its the same diameter as one of the idler wheels and if was ment to be replaced as a unit only, wouldnt the tensioner wheel  not be removeable?)

( Very appreciative of the italian juxtaposition of wonderful engineering and simple solutions. This, sometimes precarious..
Am always anxious when torqueing steel bolts into the alloy block in case threads are stripped)

A Re alignment of rear passenger wheel as its wearing out the tyre after replacing one of the pressed steel rod-arms.

Have been researching on the alternator and so far this is where Im at with the hypothesis that its an alternator regulator problem, where the regulator isnt responding to load demands and energising the rotor enough.

Not an earthing issue as a fully charged battery helps a lot.
Not a diode issue as using a Mechpro 830b  multimeter  set to measure AC, the alternator isnt producing significant AC.

Voltage/amps/power sensitive instruments eg temp gauge, fuel gauge, some warning lamps and tachometer. Malfunction when there is an electrical load put on the battery-alternator. This occurs when the headlights are switched on or during the day when the radiator fans kick in. When this happens the temp gauge jumps 30 degrees!
With suburban driving the battery slowly loses charge.
There is no current flowing when the cars shut down.
The alternator is charging when  the car idles.
The battery loses charge over time ie the alternator may not be keeping it at a fully charged state.

Research on the alternator has given.
That the V regulator is on the back of the alternator and not computer  controlled. This from the Latvian! parts supplier en.autospares.lv who have an excellent online catalogue. The regulator part no also returns the regulator on ebay. Havent been able to find this on any Bosch database yet.

From Eper using the car's vin at eper.fiat.forum, is given the alternator part no and that the original alternator went out of production 2003. Cant get an exploded diagram of the alternator tho. Am not absolutely certain it isnt controlled from the ecu.
Eper also note in a text box that the type of alternator was changed for cars with an aisin gearbox from an alternator with a star winding to one with a delta winding. Who knew! Wonder why, greater electrical draw?

(i didnt even know that there are different windings for alternators. Its interesting  that so much of civilizations advances once they enter the mainstream/paradigm are accepted without appreciation of the mental struggles and work made to reach them eg the kreb cycle Teslas electric ac motor, the mouse trap and the trip to the moon.

Which links to this story from wikipedia under Columbus egg According to Vasari, the young Italian architect Filippo Brunelleschi had designed an unusually large and heavy dome for Santa Maria del Fiore, the cathedral (Duomo) in Florence, Italy. City officials had asked to see his model, but he refused, proposing instead:

That whosoever could make an egg stand upright on a flat piece of marble should build the cupola, since thus each man's intellect would be discerned. Taking an egg, therefore, all those Masters sought to make it stand upright, but not one could find a way. Whereupon Filippo, being told to make it stand, took it graciously, and, giving one end of it a blow on the flat piece of marble, made it stand upright. The craftsmen protested that they could have done the same; but Filippo answered, laughing, that they could also have raised the cupola, if they had seen the model or the design. And so it was resolved that he should be commissioned to carry out this work.
When the church was finally built it had the shape of half an egg slightly flattened at the top.[4])"

Sorry for getting off topic.!

The next step is to eye ball the back of the alternator and replace the regulator if its there. I know this a bit like winning the battle by a broadside and not picking off a known problem (sorry Horatio but you have to go) but im not reading  the ECU-CAN  yet and the non Bosch part by Huco thru Latvia is only 26 euro.. Shouldnt be too exe in Aus if available.

Have found a French software Co that makes a good program for communicating with the cars CAN and ECU.
http://www.outilsobdfacile.com/home.php
Have already bought the Multiecuscan program. Might get this froggie one too if it works with the interface (yet to buy interface). Because it has a function to individually test each of the 4 Oxygen sensors. Havent yet found this in the Multiecuscan.

Outils have  a limited freeware version available to download. They also supply the interfaces, but the interfaces are only to buyers in Europe. Drat. Outils advised by email to test their freeware with the non Utils interface before buying a full license.
Interfaces are available that electrically isolate the lap top from the car. So neither can be zapped, But they re are more expensive. Dont know how likely a short is tho. Wireless has its benefits.
cheers

[Bobulon]

I am in awe of your commitment to fault finding. I think I would have just started hitting things, and people, at some early point in your process 

[cc]

Well. Prior to swapping out the voltage regulator, some research (youtube) gave a method of testing the regulator function at the battery.

Voltage was measured with engine and ign off, at idle, at 2000rpm with and without electrical load. I also tested a 1989 535 BMW as a benchmark.
I was hoping to see a significant voltage drop when under load indicative of a buggered voltage regulator.

First a test for AC current returned 29 for both cars. Dont know what the unit of measure is but the dial on th 830b multimeter was on 200 ACV. Concluded from this the Rectifier diodes are ok.

For the voltage test
                  A-R     BMW
ign on          12.7      -       0 rpm with headlights on
At idle        13.9      13.7                   headlights on
At idle         13.7                               headlights on cabin fan at 4.
At 2000rpm  13.5      13.4                         headlights on cabin fan 4 radiator fans on stage 1?.BMW fan not on.
When the Alfa was turned off the voltage spiked to 14V.

So the Alfa was at about 100 deg on the gauge, The transmission fault warning light was on and the Alternators voltage regulator appears to be good.
Am going to test for earths on the positive and negative sides of the battery between the Alternator and the battery next (youtube again).
I dont have 100% faith in the accuracy of the temp gauge, or that the radiator fans are switching on at the correct temp or that stage 2 is kicking in. The engine is giving off a lot of heat subjectively when the fan kicks in (at too high a temp?)
Would welcome the voice of experience from others on this.
cheers
Update a day later.

Have done some more web reading and will be taking the regulator off in situ as the brushes if they are still original, are overdue for replacement. If they are original the 210,000k means they are probably worn to stubs. The voltage 13.5V could be a little higher as measured and the 120A rating of the alternator, with the 300W*2 or 50amp draw of the twin fans (not certain of this figure). May cause the electrical continuity of the brushes to break down..
thx Bobulon, hopefully there is a happier 156 at the end of this thread.