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Discussion Starter · #1 ·
Evening,
I have no thin red wire on my alternator connector Is this OK?

I do have the thin blue exciter wire.
I replaced my alternator today as the battery hasn’t been charging and I was going to replace the connector as well (as mine wasn’t fitting correctly - turns out this was the alternator female side at fault).
Had my new connector ready and then realised I am missing a red wire.
Photos attached are from before replacing the alternator.
189930

thanks
189932
 

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Discussion Starter · #2 ·
Here is an update from what I've gathered.

The blue wire is the L terminal for warning lamp and excites the alternator. This feeds into the instrument cluster.
The red wire is for DFM which feeds into the ECU. This red wire/connector pin is apparently blank on a lot of VAG units.

I have a photo of the area on my van I taken circa 2 years ago and there is definitely only the blue wire is present, so I have had 2 years of running with no charging issues without a red wire.

So this combined with the info above points towards I am OK. I'll update again with how I've been getting on with new alternator and belt and no red wire, might be useful for someone in the future.
 

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Full of Cr*p....
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Only the blue wire is needed on the std 2.5TDi as the ECU gets revs information from a sensor in the engine/gearbox.

That alternator looks pretty "cruddy" (I guess it was the old one), but it's 99% certain you only needed the brush/regulator pack at 30 quid to fix it.
I've been "rebuilding" alternators since I was 17 (46 years ago), and old Lucas used to need diode packs, "modern" ones just need the brushes replacing after a few miles (100,000?).
Unless you are good with soldering, the only way to replace them is using the "pack".
The brushes themselves would cost less than a quid!
 

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Discussion Starter · #4 ·
Hi Or_GazM I’d say you’re probably correct there.
For me I’m happy to replace here and remove all risk of an issue, though if it was just brushes then that is a big cost difference.
Thanks for the response on the wire.
 

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Only the blue wire is needed on the std 2.5TDi as the ECU gets revs information from a sensor in the engine/gearbox.

That alternator looks pretty "cruddy" (I guess it was the old one), but it's 99% certain you only needed the brush/regulator pack at 30 quid to fix it.
I've been "rebuilding" alternators since I was 17 (46 years ago), and old Lucas used to need diode packs, "modern" ones just need the brushes replacing after a few miles (100,000?).
Unless you are good with soldering, the only way to replace them is using the "pack".
The brushes themselves would cost less than a quid!
Hi, I have recently posted a similar question in electrical concerns the blue wire on my van {1995 1.9non turbo}, I'm not sure if the blue goes to the red or black on the new connector.. There is a pic in original post, do you have any idea pal? Cheers, Bry.
 
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