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

[Tractor Dave]

On dear! You have a nasty Chinese alternator which has probably produced a voltage spike at high revs sufficient to kill your ecu.
i personally would take it back from where it came and explain what damage it has caused and get them to pay to put it right. You can buy a proper OE Bosch remanufactured alternator from a bosch service centre for £200.

[Chris5044]

Ok so I phoned the company on that sticker and got some details from them:

its an alternator for an audi a4 1.8 quattro, ASY engine code.
95-98 year

Bosch code: 0123 510 033

Does this work? or a no no?, they had to retrofit something to fit it also

[Chris5044]

The normal voltage regulation is around 14V+. Its normally printed on the back of the voltage regulator itself.
Post the specs of your alternator or some way of identify it if it is an aftermarket upgrade. I an see the advantage of having more amps but not necessarily too much voltage!

Does this help? I took some photos from the alternator, has some details on it.

[Chris5044]

The normal voltage regulation is around 14V+. Its normally printed on the back of the voltage regulator itself.
Post the specs of your alternator or some way of identify it if it is an aftermarket upgrade. I an see the advantage of having more amps but not necessarily too much voltage!

Huge thx!! I will do, once the garage gets back to me.
I just asked an ecu specialist and they quoted me £161 to fix it and test it and send it back.
The alternator does look a lot beefier than the old one for sure.

[twoqu]

The normal voltage regulation is around 14V+. Its normally printed on the back of the voltage regulator itself.
Post the specs of your alternator or some way of identify it if it is an aftermarket upgrade. I an see the advantage of having more amps but not necessarily too much voltage!

[Chris5044]

Voltage regulator is on the alternator.

I just had a new alternator fitted, would this be an issue? it is not the standard alternator

[Bowie69]

Voltage regulator is on the alternator.

[Chris5044]

That's the overvoltage protection zener. Your voltage regulator is probably shot, it blows at 18V IIRC.
No idea why it's tilted to the side though. But maybe it got hot enough that it melted the solder.

If it is what I think it is then it is not a standard diode, in fact if you put a standard diode in you'll blow the ECU fuse all the time I think.

The ECU schematics are posted in the forum, easy to verify.

Huge thank you

hmmm.. I may send it off to an ecu specialist.

can you explain what a voltage regulator is? is that in the ecu?
I dont have much knowledge on these things thx

[prj]

That's the overvoltage protection zener. Your voltage regulator is probably shot, it blows at 18V IIRC.
No idea why it's tilted to the side though. But maybe it got hot enough that it melted the solder.

If it is what I think it is then it is not a standard diode, in fact if you put a standard diode in you'll blow the ECU fuse all the time I think.

The ECU schematics are posted in the forum, easy to verify.

[Chris5044]

Hey this sounds cool, and thankyou, but diodes shouldnt just blow? Is it likely that something else could have caused this?

[Greg_S]

Yes should be easy to replace. Looks like a 1N4001 but happy to be corrected https://uk.farnell.com/multicomp/1n4...791?st=1N4001+

Hopefully that solves your issue

[jp_paul]

That's a diode - easy enough to fix it yourself provided it's a through-PCB fixture. Just make sure you fit a new one with the bar on the right side - the bar represents the line at the end of the triangle on the diode symbol.

[Chris5044]

Ok guys!! heres an update!! I have checked the fuse box now and opened it, still no signs of issue,

I managed to strip the ecu very carefully and I found something. Is this easy to fix? (its the closeup picture of the 3 connectors and one isnt looking right).

Who would be able to do this work? ecu specialist? an electronics guru or even me?

looks like a resistor of transistor im not too sure , my electrical knowledge is vague.

[Chris5044]

How are you getting on with diagnosing the issues?

Just got back from the Nurburgring trip this weekend and sorting out my life. Havent got round to looking at the s2 yet, just getting my daily, the golf top mounts done, with new tyres and front aligment doing atm.. will jump back onto the s2 when I can.. Thats the update so far. will try my best at looking at this.

[Greg_S]

How are you getting on with diagnosing the issues?