View Full Version : Alternator AEB wiring (valeo)

11-05-2015, 01:30 AM
Which 120amp Valeo would fit an AEB? All the 120 amp Valeos I've seen have a socket for the wiring while the 90amp AEB Valeo has the wires secured with a nut.

AEB Valeo 90amp

120amp Valeo

11-05-2015, 03:12 AM
Anyone have the part number of just the socket?

11-05-2015, 06:52 AM
Why do you need the 120? It will just make your car slower.

Anyway, here is the connector housing:

Here is a wire that will work. This one is probably overkill, but I always thought the OEM one was too tiny anyway.

11-05-2015, 08:34 AM
Why do you need the 120? It will just make your car slower.

Is that connector used in any other part of the engine wiring harness?

Not sure if my alternators dead or just needs more juice. Already replaced the regulator from an alternator that had bearing failure. Before I replaced the regulator, the voltage drops to slightly below 12v at full load. This is all observed using the cluster voltmeter, confirmed by engine sputtering at idle when it drops close to 12v.

When engines cold, voltage is ~14v, lights and ac on. When it warms up, lights on, a/c on, voltage drops to just above 12v. When cold, voltage would drop (~1v from starting) when a/c blower is set to max (lights off, compressor off)

Ground strap on engine mount checked. Batteries around 2months old.

Also have other power hogs (Wahlbro 450 and Meth pump), figured might as well upgrade to a 120.

11-05-2015, 09:26 AM
I have a 90A. If I turn everything on, voltage dips to 12v at idle. It is expected and doesn't cause any problems. If I was camping out in parking lots all day watching people (full creeper status), and I needed everything to be on full blast, then I might want to upgrade to a 120A. But I'm definitely not doing that. I usually just shut the engine off when I watch people from my car.

Car should still run fine at 12v. Actually, it should run ok down to 10 volts or so. Not sure what you're sputtering is about. Seeing as you've added extra electrical do-dads, it is an easy upgrade.

For the connector, I'm not sure if there are more of them on a B5. They use them on the newer cars (like Mk6 VW) for the horn connections. Looking for other applications.
Also used on the 2.0T High Pressure Fuel Pumps.
Also used on the ServoTronic connector (on steering rack) for D2 A8's and such fancy things, so equipped.

11-05-2015, 10:10 AM
I have a 90A. If I turn everything on, voltage dips to 12v at idle..

Does the 120amp do this normally also? I have a friend that has a 120amp, his dips to 12v as well, not sure if its normal though.

Mine barely goes up with RPM (ie cruising at 3000rpm). Once it goes down to 12v it stays there until the next startup.

Sputtering is caused by the tune, need to play with the voltage compensation and injector scaling. Just used it to confirm that voltage is getting lower.

Any 120amp will work (bosch or valeo), as long as it comes with the pulley right?

11-05-2015, 10:27 AM
Mine runs at ~14v with no loads (according to cluster). Using any power windows will cause it to dip to about ~13v until the window is finished going down or up, or if I'm running the AC it will fall to ~13v. Headlights have no effect on voltage in my car.

I want to say, though, that I think the mounting brackets are different between the AEB and AWM engines, so using one from an AWM might be a no-go. They offer 120 AMP alternators for your application, but they don't look cheap...

11-05-2015, 05:58 PM
Since I am actually planning to do this on mine (I have added heated seats, two full electric radiator fans, s4 hids, and plan on adding a small amp in the future), My volt guage nose dives when stuff is turned on (It is new from Napa). So I get that I have one wire going to mine, but with the plug version what does the other pin go to?

11-06-2015, 12:13 AM
The wire goes to the instrument cluster and then, from the cluster it goes to terminal 30 (battery). Inside the cluster, as part of the wiring, there is a diode that prevents electricity from flowing from the alternator. If I remember correctly, when the alternator is not running, the wire end that connects to the alternator (the plug) becomes a ground point for the battery indicator lamp on the cluster and the light comes on. When the alternator is working properly, it will provide power to the wire as well (however, since neither end is a ground point now, nothing happens except that the battery indicator lamp is no longer on). The diode prevents any electricity from surging in the wrong direction (from the alternator). Hope that made some sense...

11-06-2015, 06:21 AM
Sort of. So it just tells one of the warning lamp to either come on or not. Huh. Figured it had to do with the magnetic field or something like that. Well if it is just that simple i can live with that. Thanks!

11-06-2015, 10:13 AM
Yes. So, if you aren't using it (i.e., not connected), the battery indicator light will never come on, and you won't know if your alternator is working properly or not...