Alternator from ebay

[amlav]

Thought I'll let people know about my experience replacing my alternator on my MK-6 2.4 TDCI 2006 (VJ).
The clutch pulley had a bit of free movement when checked it (felt like being loose). After a bit of research concluded that it should be replaced and to be on the safe side decided to replace the all alternator .
Picked one up localy that was advertised on ebay brand new and being the correct one for my trany . It was a legit new car parts bussiness.
Checked all connections and plug shape , fixing holes , all matched . Took it home , removed the old one and plonked the new one up and started the engine .
Red battery fault light did not go off . Checked if maybe I missed something on cable and plug but everything was fine ...so back to work.
Removed the new alternator and took some measurments with a multimeter and compared them with readings from the old one .
I found the reading on the 3 pin socket (only 2 pins are used) where different . On the new one resistance accross the 2 pins whas 270Kohm but on the old one was above 2Mohms . Reinstalled the old one , pluged and reconnected everything , fired up and red battery light goes off as normal .
More likely I'll have to get a genuine one rather than an aftermarket one . Probably is nothing wrong with the new one but internaly is not the same as the OEM specifications . Just don't take everything advertised for granted .
Andrei

[Altransit]

Sounds like the diode pack in the new one was faulty
Normally if the alternator can be fitted, and plugged in, without any modifications, then it should work

[amlav]

Had the new alternator replaced with a second new one but same story , battery fault red light came on and stayed on . So back again with the old one and everything
is fine .
Definetly must be different electronics inside the new ones compared with the OEM one I have .
I just got a new clutch pulley and I'll just replace it . Will see how long the brushes and bearing will last on the alternator itself .

Cheers,
Andrei

[Altransit]

Did you check the running voltage outputs from the 'faulty' new ones

[amlav]

No . I did not check any voltages . The fact that the pcm does not turn the battery fault light off was enough for me to conclude that it is not same as OEM-ones .
Cheers,
Andrei