That sucks Mr. Krabs, for future reference you can rent the fan clutch removal tool at autozone for free.

 

Yeah, except they had no idea what I was talking about. One of the guys at my local autozone handed me a set of metal brushes after I asked for "voltage regulator/brush assembly"

Yeah, sucks big time.

 

The following is a continuation of this topic that I had w/ Mr. Krabs (you'll need to read bottom to top). Hope it has some helpful info:

David,
The alternator saga is over. I ended up running through the tests suggested in the link below. Testing the regulator showed that it was functioning correctly (although the test will not show if the brushes are making enough contact). But I found I had an open circuit across the two contact rings on the rotor. Never had that happen on an alternator before, but there's always a first. Anyway, I followed your lead and got one from NAPA for $200, which was less than the core charge Audi wanted. The new alternator is a Bosch (I think) vs. the original Valeo I had. I did notice that the Valeo pulley causes the belt the skew about 1/8" forward with respect to the rest of the belt train. Audi told me this when I inquired about a replacement alternator from them. They wanted $120. So while it works as-is, I do plan on changing the pulley when I do my timing belt in the next month or so. Hopefully I can get a pulley from the junkyard or maybe VW has it cheaper.
Thanks again for all you assistance. I'm going to post this conversation on the Audi forum.
-Marc
-----Original Message-----
From: Dave
Sent: Friday, October 12, 2007 12:49
To: Marc
Subject: Re: Audi voltage regulator
Martc,
> The brushes are short, but still plenty of travel left on them
Audi specifies maximum of 5mm wear. What visually looks good doesn't necessarily mean will work properly. My old regulator was exactly the same.
> What were your initial symptoms on your Audi?
Did not notice light, or gradual voltage dropping. I think it dropped and the Bat light came on at the same time, thus the alternator itself a suspect. My brushes were pretty worn, so they would have gone out sooner or later. Also, I did find a black plastic bit inside the alternator coils, that indicated to me some foreign object fell into it (one of my radiator fans had recently shattered in pieces) and caused some damage. I also noticed that the field (rotor) had poor insulation, flaking in places, this also could have been a problem.
There was one other test I did but you have to be VERY careful. I run a pinch probe to the positive output of the alternator and attached the other end to multimeter in order to measure voltage with engine running. I got 0 volts. Alternator was not outputting anything I would expect that just the worn brushes would at least output something.
> Could you take a picture of your regulator?
I do have a picture at home. Will email you.
> Did it fit correctly when you installed it?
Yes, it did fit exactly as original except I had to snip the plastic bits on the alternator plastic cover from inside, as I mentioned before. If you look at your regulator transistor, you will see several pins. The VW version has pins enclosed and has a metal piece on top in addition (heat radiator to keep it cool?).
> I also spoke with someone here at work, and now have a clear
> understanding of how the regulator works
Yeah, the reg is basically a transistor which opens and closes at certain voltages, in this case it's open > 0v < ~14v, and closes at > 14v to protect your car's electrical circuit.


> David -- First off, I do plan on posting our correspondence on the
> Audi forum. Just easier for me to use e-mail here at work.
>
> Pulled the alt out of my car last night. It came out fine, so I
> appreciate your tips on that. I removed the volt reg (see pictures).
> The brushes are short, but still plenty of travel left on them (see
> the scribe mark where the brushes went into the brush housing when
> they were compressed against the contact tings.)
>
> I cleaned up the contact rings, and reassembled everything. There's a
> bit of play with the bolt holes of the volt reg, so I tightened it
> down such that it was at it's closest limit to increase brush spring force.
> Got everything back into the car, and still not output. Not sure if
> this tells me anything, but I would have thought this would have got
> things working, at least momentarily.
>
> Question: What were your initial symptoms on your Audi? I went for a
> couple of days where the batt light would come on, then go off. Then
> it was on constantly, and the voltage just kept dropping on my volt meter.
>
> Could you take a picture of your regulator? Did it fit correctly when
> you installed it?
>
> Next step is to go home and test the regulator per the troubleshooting
> guide. I also spoke with someone here at work, and now have a clear
> understanding of how the regulator works, so I can add a couple of my
> own checks.
>
> After 5pm, please respond to my home account e-mail of:
> marcmyword@aol.com.
>
> Thanks!
>
> -Marc
>
> -----Original Message-----
> From: > Dave
> Sent: Thursday, October 11, 2007 19:50
> To: Marc
> Subject: Re: Audi voltage regulator
>
> Marc,
>
> As promised, here is the link for testing the alternator and much more:
> http://www.humanspeakers.com/audi/alternator.htm
>
> David
>
> On 10/11/07, Dave > wrote:
> > Forgot to include URL to the thread:
> > https://www.audiforums.com/m_635468/mpage_1/key_/tm.htm#635468
> >
> > ---------- Forwarded message ----------
> > From: Dave > > Date: Oct 11, 2007 12:04 PM
> > Subject: Re: Audi voltage regulator
> > To: " Marc >
> >
> >
> > Marc,
> >
> > > I would like to see a copy of that alternator test procedure.
> > I'll email it to you when I get home this evening. Please remind me
> > if
> I forget.
> >
> > Audi PN was: 06B-903-016-G, but no Audi dealership I called (about 5
> > of them) would sell me (or even could acknowledge there was such
> > part)
>
> > the OEM regulator. They all happily quoted me $650+ for new
> > alternator. (check out
> > http://www.audiusa.com/audi/us/en2/dealer_locator.html for your
> > local dealer).
> >
> > I got this 06B-903-803-B VW regulator part number by reading some
> > forums (sorry, don't have link anymore). Basically guy had the exact
> > same Audi/Alternator (he had photos) and replaced it with the VW part.
> >
> >
> > > I do recall reading that the thread on the viscous clutch is
> > > left-handed
> > That's what I've read and I almost broke the thread. The bolt was a
> > bit tight so I could not figure out which way I should turn. I made
> > up
>
> > a quick draft for you to look at (attached) as far as which direction.
> > I (actually my neighbor) had to secure the axis in front of pulley
> > (one that joins and is visible between the pulley and fan clutch -
> > less than an inch space there) with a big pliers (the type the
> > plumbers use), and turn the allen wrench CCW as you are looking at
> > it from the back of the pulley. Before this I tried to secure the
> > pulley by the holes it has against the notches on the side of
> > mounting assembly. They broke off. We also tried with a strap wrench
> > (you know the kind that looks like oil filter wrench), but it kept
> > slipping off the side of pulley.
> >
> > > I do have a pneumatic impact wrench so if I need to pull the
> > > pulley,
>
> > > I should be able to do it at home
> > Yes, the pneumatic impact wrench will knock it right off. You may
> > need
>
> > to secure the pulley with the strap wrench a little, but otherwise
> > the
>
> > momentum of the impact wrench should turn the nut without securing
> > the
>
> > pulley too tight.
> >
> > This is turning into quite a discussion, may be we should post our
> > messages in the same order on this thread, for others to benefit.
> > What
>
> > would you say?
> >
> > Thanks,
> >
> > David
> >
> >
> > On 10/11/07, Marc wrote

> > > Dave-- thanks for the quick and detailed response. First thing,
> > > I'm
>
> > > going to go home tonight and remove the alternator, and pull out
> > > the
>
> > > existing regulator (and try to do the test you mentioned tomorrow
> > > at
> > > work) and make sure the p/n matches the one you had. In the mean
> > > time, I would like to see a copy of that alternator test procedure.
> > >
> > > This was so simple in my VW and BMW...about $20 for a new
> > > regulator,
>
> > > 30 min work (less in the VW), and I was good to go for a couple
> years.
> > >
> > > I do recall reading that the thread on the viscous clutch is
> > > left-handed (CW to loosen)? I do have a pneumatic impact wrench,
> > > so
>
> > > if I need to pull the pulley, I should be able to do it at home.
> > >
> > > Tanks again,
> > >
> > > Marc
> > >
> > > -----Original Message-----
> > > From:
> > > Of Dave > > > Sent: Thursday, October 11, 2007 11:06
> > > To: Marc
> > > Subject: Re: Audi voltage regulator
> > >
> > > Marc,
> > >
> > > Yes, I still have the regulator in its original box, and
> > > everything (screws, and small manual).Its an assembly that includes brushes.
> > >
> > > I got it from a local VW dealer. for approximately $134 with taxes.
> > > Other dealers quoted me upwards of $160+taxes. Dealers do not
> > > accept
>
> > > returns for electrical parts (they warned me about it in advance),
> > > but I never got around putting it on eBay.
> > >
> > > If you want it, I can sell it to you it for $120+shipping. (about
> $7).
> > > If so, you can send me a PayPal payment at following email address:
> > > tofilter+paypal+.com@gmail.com. Please include your full shipping
> > > address. I will ship it to you right away (will ship from KY,
> > > Ground/USPS). If you need faster shipment, please email me and I
> > > will get the cost.
> > >
> > > > So I'm fairly confident it is the regulator.
> > > That's what I thought, but in my case, regulator did not help, it
> > > was the wire coils or diodes (did test with multimeter). After
> > > trying the regulator, the alternator was not outputting any voltage.
>
> > > So I ended up buying the new alternator and installed it myself.
> > > In the end, I wished I had gone with the new alternator to start
> > > with, would have avoided buying a new regulator I now don't need -
> > > so keep
>
> > > this in mind if you decide to buy the regulator. Best way would be
> > > to remove the old regulator and test it with variable current tool.
> > > Basically, you start by running 0 volts to the regulator and
> > > gradually increase the output until the regulator cuts off at
> > > about
> > > 14 volts. I have a link to a nice write-up by a guy on how to test
> > > the entire alternator. Let me know if you want the link and I can
> email it to you when I get home from work.
> > >
> > > One other thing for you to be aware of: When I was trying to
> > > replace
>
> > > the regulator, I had to snip (with pointed pliers) plastic beach
> > > ball shaped recesses on the inside base of alternator plastic
> > > cover,
>
> > > since the VW regulator had straight grooves as opposed to kind of
> > > star shaped on Audi. After this the regulator fit nicely.
> > >
> > > > Appreciate any assistance you can provide.
> > > I will be more than happy to give you some pointers as to how to
> > > remove the alternator and install the regulator. I actually took
> > > some photos during removal. It was a piece of cake once I removed
> > > the fan viscous clutch pulley, which was giving me a lot of
> > > trouble until I figured out how to remove it easily. Once I
> > > figured out how,
>
> > > it was very easy. If I had to do it again, the whole job, would
> probably take me 40 mins.
> > >
> > > Also, be aware that if you buy a new alternator, it may not come
> > > with alternator pulley, and its kind of hard to remove from your
> > > old
>
> > > alternator to move to the new. You either need a special tool, or
> > > an
>
> > > air wrench, there is no other way that I know of. I can give you
> > > some pointers on how to remove it without special tool and with
> > > air gun, just drop me a line if you decide to go with new alternator.
> > > Otherwise, you may need to make a trip to a friendly repair shop
> > > that will move the pulley between the alternators for you (I would
> > > give the guy a $5-$10 for this).
> > >
> > > Let me know if you have any questions,
> > >
> > > David
> > >
> > > On 10/11/07, MarcMyWord from Audi Forums
> > > wrote:
> > > > Well, my friend, it looks like I'm in the same boat as you. I
> > > > have a
> > > 2001 A4 with the Valeo 120A altenator, and I have a bad regulator.
> > > Was quoted $580 for the altenator, and $120 for the new pully I
> need.
> > > >
> > > > The same symptoms have happened on an old VW Rabbit I had
> > > > (several
> > > times -- all solved by a new regulator), and my old BMW. So I'm
> > > fairly confident it is the regulator.
> > > >
> > > > Can you give me some info on where you found your replacement
> > > regulator from VW? Do you still have the one you purchased?
> > > >
> > > > Appreciate any assistance you can provide.
> > > >
> > > > -Marc
> > > >

 

I see that is super old and I dont want to bother people who have long forgotten about this thread, but it came up during my search for the regulator so I'm gonna post it for anyone else looking. but I found the regulator here for what seems to be half the price of what the dealer wants. http://americanenginesco.com

I also found it on ebay for a lot less than the dealer. Moral- there are many ways to avoid going to the stealer.

 

This is the same regulator transister that's on my 2001 a4 b5 2.4L
Its option code is 8gl and the alternator # is unknown at the moment as I'm just going to replace the worn brushes.
That saves taking it out.
Theres no other part # on it except for the plastic housing #'s

I got another 120 amp alternator, its off a diesel Audi.
Model # 059 903 015g
Its regulator#s transistor # is
st U098
2542463
32208 00 47
There's a part # ink stamped onto it, I will update this info tomorrow
I don't think there's much difference between all of the regulators as long as the amps are the same.
Is this correct?

Otherwise the pullys seem to be a wide range of diameters, like only a 1/2 mm or two difference, probably other differences like ribs and position out from the alternator.