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AFN Alternator: Connect Terminal W to 120A

 
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dokatoto
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Post14-06-2005, 7:13    Subject: AFN Alternator: Connect Terminal W to 120A Quote

Hello,

I have a 98 AFN engine in my VW T3 and need a signal from terminal W of the alternator for my tachometer and dynamic oil pressure control.

Okay, I've found the letter 'W' on the lemon juice bottle cap. When I remove the cap, a screw is visible underneath, but for some reason, I'm not getting any signal on the tachometer (RPM gauge).

Can I measure this signal with a multimeter, and what value should I expect to see?

Could it be that something needs to be adjusted on the LIM (likely referring to a control unit or module) in order to access terminal W?

Regards,

Toto.


Translated on 07-08-2026, 7:31.
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t3_tdi
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Post14-06-2005, 8:35    Subject: AFN Alternator: Connect Terminal W to 120A Quote

Sure, here's the translation:

'Hi there,' or 'Hello.'

If you look inside the alternator housing, you can see where the different windings are connected (wires with small rings are crimped together). If you hold your cable there while the engine is running, you will see that your tachometer needle fluctuates.

You still need to calibrate the tachometer. There's an adjustment screw under the sticker on the back of the tachometer. If the calibration isn't quite right, it might be because you need to use a different coupling that provides different frequencies.

Good luck!

Best regards, Gunnar.


Translated on 07-08-2026, 7:34.
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dokatoto
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Post14-06-2005, 8:59    Subject: AFN Alternator: Connect Terminal W to 120A Quote

But that's exactly the point. Why does the lid already have a 'W' printed on it? And underneath is a socket with a long screw inside, which would be perfect for attaching an eyelet, but there's no signal coming from it...

Can I not measure the signal with a multimeter?


Translated on 07-08-2026, 7:35.
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dieter
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Post14-06-2005, 11:53    Subject: AFN Alternator: Connect Terminal W to 120A Quote

Quote:
If it doesn't work out exactly with the oak, it might be because you need to use a different type of joint, as these produce different frequencies...


How did you come to that conclusion? The frequency depends on the speed and design of the generator; nothing else matters.

Quote:
Can I measure the signal with a multimeter, and what should I expect to see displayed?


No, you can't. A multimeter will show approximately half the on-board voltage in the DC voltage range; you won't be able to see anything more than that.

Since generators usually don't have a W-terminal, nothing will likely be connected there. So you'll have to do it yourself. The connection needs to be made to one of the three winding terminals. There are several guides available online on how to do this. For safety reasons, you should connect a resistor (1kOhm) in series directly to the terminal; otherwise, it could spark quite a bit in case of a short circuit.

Greetings,
dieter
T3 syncro 16 AFN
- steckenbleiben, wo keiner hin kommt -


Translated on 07-08-2026, 7:38.
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