Car Broke down! :/ after full revs Any help /advice?

[LSG]

That's great news Chris. Pleased your getting things sorted out. Regards Lynn

[Chris5044]

Huge thank you to everyone for your help!

New plan of action:

Found refurbed bosch alternator off german ebay - bought (£230 euro)

testing old alternator next week at electric specialists next week, then selling or going further on that to get money back.

sent off ECU today to ECUTESTING on the internet..

Then get car running after this and getting a friends work collague (electric specialist) to thoroughy test the car for piece of mind.

Boom then done!! --- back to maintenance -- cambelt and full service and care treatment.

[piotr]

This is so obvious that alternator on our cars is regulated internally.we talking about car from 90s that has not got any communication network like CAN bus or LIN .if it was controlled by ECU it would have battery monitoring module fitted on negative post on battery with communication line connected to it that can report back the message of battery state of charge ,temp another info and base on this the charge output would be regulated. This is not the option on S2 I'm 100%sure

[Chris5044]

[twoqu]

https://www.woodauto.com/bom/35112/BOSCH-0123510033

If you look through the parts that constitute the alternator fitted you will see the Regulator. That means that alternator is internally regulated and not as suggested by any other means.

[twoqu]

No! Point 4 relates to the fact that the alternator fitted according to the Bosch part number you were given is also internally regulated and therefore not capable of being controlled externally. Its relatively easy to verify if you do a bit of checking. You can then confidently rebut the lies you are being told with facts. The A4 B5 model that alternator fits is also not capable of controlling the voltage of an alternator. Like the correct S2 one, it is also internally regulated! From what I can tell this capability is not possible without Canbus and our vehicles are from the wrong century.
The problem really I think is the pulley which is probably unique. Which is why I have been banging on about getting it back unless it has been fitted to the alternator on the vehicle. As I said previously and others have proved from the threads linked to, the alternator itself is a common fitment on other models of Audi from a similiar vintage. The difference in the part number represents partly the model designation and the differences in the rear cover and pulley. For example the alternator was also used on the S6 C4 with changes to the pulley as it ran a 6 rib belt whereas the S2 used a 4 rib belt.
If the pulley has gone it will never function as intended. Although if you want someone to bodge something back on, then that will also be possible because as long as its attached with a belt and hooked up to the car correctly then it should generate voltage/amps when spun. So basically you need to work out why, in your case, this has not worked.

[Tractor Dave]

I struggled finding a new alternator for my S2 Avant but your local Bosch Auto centre can supply a factory refurbished one for £200. Mine looks like a brand new unit and was a perfect fit. They need an exchange unit. Suggest you attend your local breakers who I'm sure will provide you a broken Audi one cheap as chips

[Chris5044]

From the information provided we know the following:

1. The S2 Model was not produced with the capability to regulate the voltage output of the alternator.
2.. The correct alternator will be internally regulated via the voltage regulator at 14.5V.
3. The Motronic ecu on the S2 does not have any pin assignments to either accept or send signals to monitor load or control voltage output. I am not aware of any other module on the vehicle that has that capability.
4. The alternator fitted according to the part number is also internally regulated.

If it was hooked up with the factory wiring it cannot be controlled. It is dumb in that sense. If it was not faulty it should have functioned as expected. Why it was necessary to modify an alternator to fit when as discussed the correct variant was available is unknown.

Hey thank you, this all makes sense, but the last number 4, they said that they dont do alternators for my vehicle anymore, many shops/garages say this.

So as the customer I'm just doing what I can.

It looks like I will now have to source an alternator that will fit and hope that It will work and be reliable.

[twoqu]

From the information provided we know the following:

1. The S2 Model was not produced with the capability to regulate the voltage output of the alternator.
2.. The correct alternator will be internally regulated via the voltage regulator at 14.5V.
3. The Motronic ecu on the S2 does not have any pin assignments to either accept or send signals to monitor load or control voltage output. I am not aware of any other module on the vehicle that has that capability.
4. The alternator fitted according to the part number is also internally regulated.

If it was hooked up with the factory wiring it cannot be controlled. It is dumb in that sense. If it was not faulty it should have functioned as expected. Why it was necessary to modify an alternator to fit when as discussed the correct variant was available is unknown.

[k.alle]

If I'm reading this thread right and you do in fact have a ECU regulated alternator the switch from china copy to bosch wont help you.
You need a standard S2 alternator which regulates itself.
Or else you might have the same issue again.

I bought mine from German ebay (bosch refurb), which was intended for an S4 AAN engine.
All I had to do was switch pulley to ABY and rear plastic cover as others have pointed out here as well.

IIRC it was around 140-150 € delivered for the 120A version, including the cost for not providing my old alternator as exhange.

[Chris5044]

Two years ago I had my alternator rebuilt by a local company. It lasted about 10 miles then just stopped charging.
Took it back and they fixed it, then it lasted about 5 miles and died again.
They insisted there was nothing wrong with it and it was something else on the car causing it to die, they fixed it again anyway. Sure enough it broke again.
So I bought a new original and it’s been fine ever since.
Cheap Chinese internals were used I reckon.

oh my!

[martinjs]

Two years ago I had my alternator rebuilt by a local company. It lasted about 10 miles then just stopped charging.
Took it back and they fixed it, then it lasted about 5 miles and died again.
They insisted there was nothing wrong with it and it was something else on the car causing it to die, they fixed it again anyway. Sure enough it broke again.
So I bought a new original and it’s been fine ever since.
Cheap Chinese internals were used I reckon.

[steve briance]

If I'm not missing something, are you going to spend more money with the garage that caused all this bother in the first place? Why would you do that?!

[Chris5044]

Hey huge thx guys!!
Sorry also for the confusion, but I think i need to explain that the 2nd time of attempting to test the alternator I took it to a different place top get tested and they said that new info about that they cannot test those ones because of the smart charge system.

The 1st test was from the original supplier and they said they tested it for 1.5 hours... which also the 2nd testing place said that that is ********.

So its like a game of chinese whispers..

I guess I will take this on the chin .. but I need to source a suitable part for this car and I have asked the original garage to see if they can do that now .. but a bosch one.. As they supplied the other they could end up giving me one and using the surcharge, though I did fail to tell them in the first place to fit a bosch one.. though I wouldnt of expected an alternator to go like this .. and the chinese stickers say a lot. :/

I'm wondering if I can hold the original supplier to account if this all works and ecu fitted and I get the whole car electric tested once all fitted ..

hmmm :/

[twoqu]

If the specs are correct then the alternator fitted has a 56mm V5 groove pulley whereas the correct spec is a 70mm V4 groove pulley. Could really do with getting at the least your old pulley and plastic cover back. In a sense alternators are dumb ( not as dumb as the people selling or fitting them apparently) and don't know what vehicle they are connected to, could be an S2 or a Saturn V to be topical. Bosch probably make one casing and internals for a certain output and Audi add a different pulley or rear cover and hey presto another part number appears! In theory it should have worked and put out 14.5V. That does not appear to be the case here.
Anyway, hopefully there is a way forward. Either go with a used one and take a punt ot get a recon/new one from a reputable source.
Obviously we were not parties to what was agreed but the facts are an incorrectly sourced alternator appears to have caused an overvoltage issue and damaged the ecu. Somebody is not telling the truth over the testing, sadly perhaps both! Thats why you should have got it tested independently. Still, the ecu repair confirming an overvoltage issue would probably be enough to warrant at the least the threat of a claim. Not that is of much use presently.