Alternator Voltage Regulator Assembly Part

KentSzabo

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I have been reading the posts regarding the Golf A4 TDI Alternator Brush/Voltage Regulator assembly. Many posts referred to prices for this part from $45 to $80, yet the only post of a URL for 1stvwparts.com lists the assembly for $147. If anyone knows where to obtain this part for the $45 to $80 range please post the url. I don't need it yet, but my 2002 has 130K on it and it would be nice to carry this part on long trips.
 
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PDJetta

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Can't you just solder new brushes into the regulator for a few bucks? That's what I did on the A1s and A2s.

If you can, where can you buy the brushes?

--Nate
 

ymz

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It also depends on the manufacturer of your alternator... some of them do not have replaceable regulators...

Yuri.
 

mk3

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alternatorparts.com ....may work

I just rebuilt the 120A Bosch Alternator on my B4 Passat VR6.

I got the bearings from McMaster-Carr and the TRANSPO voltage regulator/brush assembly from the above website.

I am not sure how you can verify the part number without taking the part out and reading the number (which is what I did).
 

KentSzabo

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I don't think there is a brush/voltage regulator assembly for the Bosch alternator on the 2002 ALH engine. I have been searching for hours with no success.
 

ymz

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Actually, I believe that Bosch is one of those that does have a replaceable voltage regulator/brush holder...

I'll see what I can dig up...

Yuri.

Edit: from somewhere on this site:

If your 120 Amp (Bosch) alternator is P/N: 038-903-018-B or BX you need a voltage regulator P/N 038-903-803-E

Another edit: (from elsewhere on this site:)

There are three versions of alternators that were installd in the ALH (120 amps).
Bosch
028-903-028E (Type 15)
012-903-025K (Type 18)
These alternators used voltage regulators P/N: 06F-903-803A

Valeo
038-903-023-S (type 31)
Voltage Regulator 06B-903-803

Hitachi
028-903-029G
Voltage Regulator non-serviceable

It looks like Impex carries the Bosch voltage regulator
 
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Joined
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KentSzabo said:
I have been reading the posts regarding the Golf A4 TDI Alternator Brush/Voltage Regulator assembly. Many posts referred to prices for this part from $45 to $80, yet the only post of a URL for 1stvwparts.com lists the assembly for $147. If anyone knows where to obtain this part for the $45 to $80 range please post the url. I don't need it yet, but my 2002 has 130K on it and it would be nice to carry this part on long trips.
Usually the brushes will last up to 200k miles easy.
Depending on if you have DRL and other stuff running all the time they could last up to 250k miles.

Brushes are integral with the regulator assemble.
 

Powder Hound

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One thing you must look at if you replace the regulator is the condition of the slip rings.

Bosch uses a lot of copper in the brushes. It makes the brushes harder so they last longer. It also wears out the slip rings. The end result is that if you have to replace the regulator for worn brushes, chances are the alternator must be disassembled so that new slip rings can be pressed onto the armature also. The fun part of this operation is that not many shops have the parts and press to do it.

Please take a good look at the slip rings if you remove the regulator for any reason.
 
Joined
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ymz said:
Edit: from somewhere on this site:

If your 120 Amp (Bosch) alternator is P/N: 038-903-018-B or BX you need a voltage regulator P/N 038-903-803-E

Another edit: (from elsewhere on this site:)

There are three versions of alternators that were installd in the ALH (120 amps).
Bosch
028-903-028E (Type 15)
012-903-025K (Type 18)
These alternators used voltage regulators P/N: 06F-903-803

It looks like Impex carries the Bosch voltage regulator

Impex told me the regulator was $120 and it was better to buy the alternator.
I got the regulator from https://www.1stvwparts.com for $50+

Thinking outside the box is most times, better.
 

PDJetta

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Powder Hound said:
One thing you must look at if you replace the regulator is the condition of the slip rings.

Bosch uses a lot of copper in the brushes. It makes the brushes harder so they last longer. It also wears out the slip rings. The end result is that if you have to replace the regulator for worn brushes, chances are the alternator must be disassembled so that new slip rings can be pressed onto the armature also. The fun part of this operation is that not many shops have the parts and press to do it.

Please take a good look at the slip rings if you remove the regulator for any reason.
Makes perfect sense. On the old A1s, the brushes appeared to be pure graphite and they failed at about 90,000 miles. I think I read here that the new regulator brushes last 150,000 to 200,000 miles.

--Nate
 

mk3

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my slip rings on the 120A bosh alternator (From 1995 Passat VR6 with 195k miles) were worn noticably but I decided not to attempt replacing them. I guess the smart thing would have been to measure the diameter - the nominal is 14mm but of course I do not know the exact new DIA, nor do I know the wear limit. I did polish the slip rings with 800 grit paper.

I spent less than $60 (but lots of time) rebuilding the alternator and I did not get new slip rings. if you can buy a _good_ rebuilt alternator for $120 then I think that is a good value.

in my case, I was interested in learning how the alternator was built and I liked the challenge of saving a little bit of money.

to each his own...
 
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