Alternator not charging solution - Polo 9n

Chat about your 9n Polo (inc GT and Fun)
Posts: 17
Joined: Tue Jan 15, 2019 12:57 pm
Drives: 1.4TDI 2008
Location: West Mids, UK

Re: Alternator not charging solution - Polo 9n

Post by slicker55 »

CarbonChaos wrote: Wed Jun 09, 2021 7:09 pm By earthing a wire you are testing the circuit, as in your previous post your battery light does illuminate under certain conditions this seems pointless. I’d be fitting an alternator
Thank you for replying and for your advice to replace the alternator (a new one is on order)...

In the meantime, I decided to do the test anyway, earthed the blue wire and switched the ignition on (engine not started) - battery light did not illuminate. I then repeated the same test with the brown wire but still no battery light...

I'm pretty convinced the alternator is faulty - we should know for sure when the new one is fitted - fingers crossed!

So, to wrap things up... as the battery light comes on when the engine is revved, no need to do any more testing for breaks in the wiring but could the problem lie somewhere else... thinking about ECU, Onboard Power Supply Module etc... or am I just getting a bit carried away and over-thinking things?
Posts: 1
Joined: Mon Nov 22, 2021 3:43 pm
Drives: Polo 9N 53 Plate 1.4Tdi
Location: North-West England

Re: Alternator not charging solution - Polo 9n

Post by PercyPig »

Just joined to thank Drewbar for the post. Fixed the 2 wires as per your post, mine were Blue and Green/Purple.
Here's a new link to purchase a pre-wired connector:

Splice it in with soldering and shrink wrap, and hey presto the Battery light is back and existing alternator kicks in as it should.
If you want a VAG connector that you'll wire yourself this is the part No. 1J0973722, but far easier to get the pre-wired.

Many thanks again.
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