new vs rebuilt alternator...cost & quality

Greeting, this is my Maiden Voyage - ist posting. I want to know what the cost would be and which is a better choice for an alternator for 2003 530i. How much is a new one vs a rebuilt one?

Also, they told me that the Alternator could not be rebuilt. Should I get it back from them?
I have a feeling they will keep the old one and rebuild it to be sold later and in the meantime they will sell me another...The old "Razzle Dazzle". What ever happened to honesty?

Info would be appreciated as I will return to the mechanic on Monday. If it is a new Bosch as opposed to a rebuilt one, how can I verify that the part is indeed, new?

thanks,
Q

Rebuild yourself. I posted a DIY in the forum, search for it.
Should not cost more than $60, your own labor.

If you need a 2nd opinion, my cousin has a BMW shop in Gardena CA:
18020 S. Vermont
Gardena, CA 90248
310-532-3145.

Originally Posted by cn90

Rebuild yourself.

From the bestlinks thread ...
- cn90 alternator rebuild DIY

Originally Posted by bluebee

From the bestlinks thread ...
- cn90 alternator rebuild DIY

This diagram is mis-labeled, the carbon brushes is built in to the voltage regulator. The semi-circle component on the upper right is the rectifiers which are soldered to the stator. Don't quote me saying it, you can verify it from other online references.

Originally Posted by supradupe

This diagram is mis-labeled, the carbon brushes is built in to the voltage regulator. The semi-circle component on the upper right is the rectifiers which are soldered to the stator. Don't quote me saying it, you can verify it from other online references.

The caption of the picture clearly says:

- "Typical BOSCH Alternator", so this is a generic diagram for BOSCH alternator.

- "Carbon Brushes + Rectifier Combination", so in plain English, this means the brushes are built into the voltage regulator.

I cannot be more clear than this.

Originally Posted by cn90

The caption of the picture clearly says:

- "Typical BOSCH Alternator", so this is a generic diagram for BOSCH alternator.

- "Carbon Brushes + Rectifier Combination", so in plain English, this means the brushes are built into the voltage regulator.

I cannot be more clear than this.

Typical automotive alternators are all set up that way, bosch or not, don't matter.

Rectifier and voltage regulator are two separate entities. The brush is built into the voltage regulator (which you conveniently refer it as rectifier). The rectifier, also known as "diode trio", is responsible for converting ac to dc. The dc voltage is then "regulated" by a voltage regulator.

from your previous message, you repeatedly referring to the voltage regulator as "rectifier". The rectifier, i.e. the diode trio bridge, is NOT a easily replaceable part and it will fail too. The cost of a rectifier, is way over $60, and if you can find one that will fit the particular bosch model.

"4. New Voltage Regulator (a.k.a = "Rectifier")
- Here is the kicker: if checked OK, most simply re-use it but read on.... Although this is a solid-state device (no moving part), it is rated at let's say 2 million cycles of alternator revolutions, then the solid state device just fails any time after that.
- The reason most rebuilders re-use the Voltage Regulator is cost (a good Voltage Regulator costs some $50-60/each)."

Originally Posted by quinnski

which is a better choice for an alternator for 2003 530i. How much is a new one vs a rebuilt one?

I just went through the same thought process for a 2002 525i.

The price of a new Bosch 120 alternator would have been astronomical; so, there was no question that I was going to buy a rebuilt alternator. I didn't have time to rebuild it myself because it's my only vehicle; but, in hindsight, I wish I had stockpiled the components from cn90's DIY.

I got my rebuilt Bosch 120 from OEMBimmerparts for less than $200 (details here) overnight.

Originally Posted by quinnski

they told me that the alternator could not be rebuilt. Should I get it back from them?

It's my understanding that most states make it law that you get your part back if you ask for them PRIOR to them working on the car. Of course, they'll still have the parts if you ask soon enough after they start work - but the point is, if you ask right, they have to give you the old parts, by law.

I'm not sure how that applies to items that have 'core charges' ... these core charges always confused me anyway. I paid a core charge of $100 for my alternator, which cost $25 to ship back, so, the core charge, in essence, cost me $25 in real dollars.

Originally Posted by quinnski

I have a feeling they will keep the old one and rebuild it to be sold later

As I said, I don't know how "core charges" work, especially to a mechanic.
It's my guess they too will have a core charge (although I don't know this for a fact), so, they'll send the alternator back to the remanufacturer. It's my guess that the final say on whether or not it can be rebuilt will be by that remanufacturer ... but by then, it's way out of your control (or concern).

Originally Posted by quinnski

What ever happened to honesty?

I've been cheated & treated well when I went to an indy; I've only been cheated when I went to the stealer ... but I've never been cheated in a bimmerfest DIY!

My suggestion if you have the time is ...
a) Get your car and old alternator back
b) Order a rebuilt alternator from OemBimmerparts
c) Replace it yourself (here instructions I wrote up with cn90 help)

Originally Posted by quinnski

If it is a new Bosch as opposed to a rebuilt one, how can I verify that the part is indeed, new?

Dunno. My rebuilt alternator (see pic below) came with stickers on it saying it was rebuilt and by whom.

Thank you very much for your reply. I appreciate the time you took and the information you supplied. My new mechanic turned out to be fair and honest, hard to believe in this day and age where greed is the motivating factor. The mechanic and you have restored, a portion, of my faith in humanity.
-JQ

Bluebee,

The concept behind core charge is simple.

Let's say an Alternator costs $200 with "core charge" of $100.

So you get the Alternator provided you return the old Alternator so they can rebuild it and re-sell it later, making money.

Let's say you fail to return the old Alternator, the seller will charge you $100 on your VISA Card for failure to return the core, now your cost is $300 for failing to return the core.

However, if you return the core as instructed, then it would cost you $25 for the shipping; so your total cost to get a rebuilt Alternator is $225.

Originally Posted by cn90

The concept behind core charge is simple.

The part I was unfamiliar with was when an Indy does the job.

Does the Indy pay the core charge and then give it back to you in the price?

Or, does the Indy pay the core charge and then NOT give it back to you in price?

Or do the suppliers not charge the Indys the core charge and you just pay full price?

ATTN: BLUEBEE
Thank you very much for your reply. I appreciate the time you took and the information you supplied. My new mechanic turned out to be fair and honest, hard to believe in this day and age where greed is the motivating factor. The mechanic and you have restored, a portion, of my faith in humanity.
-JQ

Napa in my area sells remanufactured Bosch 120 amp alternators for $194 + $35 core charge, 90 amp is $149 + core (not sure why you would go mail order when local is the same price).

So for $35 you could keep and rebuild it, but with a lifetime warranty on the remanufactured unit, why would you need to?

And my two nearby Napa's had the alternator on the self too.

Originally Posted by manticore33

not sure why you would go mail order when local is the same price

When I needed an alternator pronto, I went to Napa in San Jose, AutoZone, and Kragen.

None had the Bosch 120 in stock. Some could get it. But it wasn't the same price as mailorder from our sponsors.

BTW, add at least $25 to the price for an alternator to ship it back to the sponsor (ask me how I know) so if the core charge is, say $35, you only get $10 net back from that core charge.

Nothing wrong with NAPA alternator. Infact, I called a few rebuilders in the US to get the detail (these rebuilders rebuild the Alternator and ship them to Pepboys, NAPA etc. etc.).

A proper rebuilding process involved. The issues for each item are in italicized letter:

1. New front bearing
- Some places put in new bearing but in 99% of the time, you get Chinese bearing instead of brand name like Koyo, SKF, F.A.G.
- Some check it, if no play, then they simple re-grease it and re-use it: not recommended.

2. New rear bearing
- Some places put in new bearing but in 99% of the time, you get Chinese bearing instead of brand name like Koyo, SKF, F.A.G.
- Some check it, if no play, then they simple re-grease it and re-use it: not recommended.

3. New brushes
- This is a must because at 140-150K when the alternator fails, the brushes are worn down.
So virtually all rebuilders install new brushes.

4. New Voltage Regulator (a.k.a = "Rectifier")
- Here is the kicker: if checked OK, most simply re-use it but read on.... Although this is a solid-state device (no moving part), it is rated at let's say 2 million cycles of alternator revolutions, then the solid state device just fails any time after that.
- The reason most rebuilders re-use the Voltage Regulator is cost (a good Voltage Regulator costs some $50-60/each).
- This is also the reason why many people run to Autozone, get a rebuilt Bosch Alternator, only to find out 1 month later the Voltage Regulator failed! Some in this forum have gone through 3 Alternators in a 6-month span. What a waste of time and effort!!!

So unless you know exactly how a rebuilt Alternator was performed, rebuild the Alternator yourself for $60.

Sadly, the day of good craftsmanship and quality work is over, many people simply go for a quick buck, but you the owners pay for this poor practice.

Originally Posted by cn90

So unless you know exactly how a rebuilt Alternator was performed, rebuild the Alternator yourself for $60

This is scary. If only I had stocked the parts, ahead of time.

My rebuilt alternator was bought from a sponsor.

At least for the sponsors, we should know what parts are put in, right?

Do we know that information for the sponsors who sell alternators?

Originally Posted by cn90

4. New Voltage Regulator (a.k.a = "Rectifier")
- Here is the kicker: if checked OK, most simply re-use it but read on.... Although this is a solid-state device (no moving part), it is rated at let's say 2 million cycles of alternator revolutions, then the solid state device just fails any time after that.
- The reason most rebuilders re-use the Voltage Regulator is cost (a good Voltage Regulator costs some $50-60/each).
- This is also the reason why many people run to Autozone, get a rebuilt Bosch Alternator, only to find out 1 month later the Voltage Regulator failed! Some in this forum have gone through 3 Alternators in a 6-month span. What a waste of time and effort!!!

So unless you know exactly how a rebuilt Alternator was performed, rebuild the Alternator yourself for $60.

the voltage regulator and rectifiers are two separate things. the voltage regulator has the carbon brushes and costs 50-60 like you said. The rectifiers on the other hand, is very difficult to source. I was not able to find suitable rectifiers for my bosch alternator and there is a lot of heavy soldering and desoldering to do if one wants to replace the rectifiers. I had rebulit mine only to find out 6 months later that the rectifiers are dead. So, going with your logic, rebuilding yourself can also be a waste of time and effort. At least if one buys a remannufactured alternator, one can get limited life time warranty and get it replaced. Rebuilding on your own, those parts are warranted only for 1 year at most and you are still stuck with a POS.

I can't speak for alternators on "lesser" cars" but as for the 540 liquid cooled one, I have not had any luck with remanufactured ones. I have a few friends that haven't any luck either so now when we have alternator issues, we just buy new. Not cheap but much less trouble in the end.

Sorry to hear that bluebee (I thought about doing CN90s rebuild, but I needed the car ASAP). Being in Central Ohio I am lucky with quick shipping from the any of the coasts (UPS/Fedex have distribution facilities here) and major part-chain warehouses are nearby. There is also Napa warehouse about 15 miles from my home and literally the Delaware Distribution Center for Advance Auto Parts and Jeg's are in my back yard (not that I shop at Jeg's). For local Napa or Advance Auto Parts stuff, I can get it same day warehouse pulls duing normal business hours. Oh, and I am friends with both of the Delaware location's of Advance Auto Part store's managers so special pulls and price matching are not a problem.

Online stuff is 3-5 days max.

Indy's pay the core charge and get the core charge refunded when they return the part. The actual cost of the part they charge is likely list. Go into an auto parts store and you will see a two costs. The list price is typically what the shop charges the consumer after performing the repair. So, when you are using a shop they make their margins on the list price of parts and book time. A lot of part stores will deliver the parts to the mechanic and pick any returns and cores and have less than retail discounts too. For instance AAP might sell brake pads to a shop for $13, charge a consumer $30, and list might be $45. If you look at the mechanics invoice for the service work the person having the work done would be charged $45 for pads, 1.5 hours book time (even if only took 40 minutes to do), then other materials.

As CN90 states, there is a wide variance in the quality of rebuilt electrical parts. I have only had good luck when I purchased rebuilt electrical parts either from the dealer (BMW/Honda/Nissan) or from an online retailer that sells products rebuilt by the oem manunfacturer (or their designated contractor), example: Bosch rebuilt alternator, or Nippondenso rebuilt starter.

Rebuilt stuff from chain storres, and independants can really vary in quality, depending on who is doing the work. Typically the chain store stuff is the worst, as they are driven by a national contract, and price is king, so they only replace what is absolutely necessary, then clean it up and paint it, put it in a box and say "lifetime warranty".

I got my rebuilt alternator for my 540 from BMW Seattle, they installed it too (emergency repair) and it was super expensive, but comes with a "lifetime warranty" that is honored at any BMW dealer in North America, parts and labor. So I basically paid $300 extra over the online price for the lifetime warranty versus the two year warranty that Bosch offers (it is the same exact Bosch factory rebuild). My understanding is if you buy the alternator from BMW "over the counter" and dont have them install it, their standard 24 month unlimited mileage warranty applies (parts and labor), not the lifetime warranty.

I have about 80k on that alternator, and hope to keep the car long enough to get my $300 back out of BMW!

My bad,

Voltage Regulator and Rectifier are 2 different entities (I took College Physics too long ago...).
In some other alternators, these 2 items are packaged together.
In this particular Bosch Alternator for BMW E39, they are located separately.

Talking about component failure, I think the Voltage Regulator fails more often than the Rectifier part.

Attached is an updated diagram:

oooooh. Nice. Thanks cn90.



FWIW ... I took college physics years ago too!

So, for newbies ... from memory of college courses ...

Voltage regulator ... regulates the voltage (presumably to ~14 1/2 volts or whatever it's set at).

Rectifier... changes the AC to DC (generally with diodes in a full-wave configuration, maybe wheatstone bridge).

Originally Posted by bluebee

oooooh. Nice. Thanks cn90.



FWIW ... I took college physics years ago too!

So, for newbies ... from memory of college courses ...

Voltage regulator ... regulates the voltage (presumably to ~14 1/2 volts or whatever it's set at).

Rectifier... changes the DC to AC (generally with diodes in a full-wave configuration, maybe wheatstone bridge).

Bluebee, You mean rectifier converts AC to DC right!

Originally Posted by 16valex

Bluebee, You mean rectifier converts AC to DC right!

ooops. Just corrected that. Sorry. What it does, for those who don't know diodes, on the positive part of the curve is it forward biases the diode until the junction voltage is overcome (I think that's about 0.7 volts so you lose that) and then lets the rest of the voltage pass through as a short circuit.

Then, on the negative part of the curve, the diode essentially blocks the (now) reverse-biased current such that only the first half wave gets through that diode ...

But wait ... if you add another diode, opposite the first diode, it then is forward biased and it allows that second upside down wave through and the whole thing is in a wheatstone bridge like configuration (someday they'll name a bridge after me ... ).

Or at least that's what I remember from college days ...

BTW, the danger isn't the voltage so much as the CURRENT. Over time, that heat from the current ruins the rectifiers as stated in this thread above.

good god does she(?)know her stuff!

From the pro rebuilder:

- When a voltage regulator goes bad, it can damage the diode trio (rectifier). But as a general rule, voltage regulator fails frequently with age.
The rectifier rarely rarely goes bad.

- A major rebuilder for Bosch in Michigan can offer:
a. New Bosch Alternator (no need for core charge because it is new): $400
b. Reman Bosch Alternator: $180 (with core charge) and who knows what parts were replaced.

Some more tids/bits:

1. To look up PNs for Alternator, this is a good website from the UK:
http://wo***********
My 1998 528i Rectifier is "RTF39818" or Bosch PN 1127319712.
http://wo***********/Component.aspx?Ref=RTF39818

2. A good supplier for rebuilders and individuals is IAT USA Inc.:
http://www.iat-usa.com/
IAT USA Inc.
61-32 2nd Avenue
Woodside, NY 11377 USA
Tel : (718) 956-4248 Toll Free: (800) 872-8890
Fax: (718) 956-4310
Email: sales@iat-usa.com