Alternator question

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TRIPPFONTAINE

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My alternator seems to have packed it in. For a while it sounded like the grinding of my wife's teeth every time I headed to the garage. W & N offer two models - An Original alternator for external voltage controller and a 55A with built in voltage controller.

Any opinions about the relative merits of these? I'm in Australia, so wondering if there is an off-the-shelf Alternator that I might source as an alternative? Opinions welcome.
 
I went with the internally regulated alternator but left the old regulator for appearances. You can check your local parts place for a Bosch internally regulated model, the one I have fit the bracket with no modifications. I do not know off the top of my head the model number.
 
I know E12s have internally regulated.

I would go w/that. My externally, original one fried the wire between the regulator/relay thing and the alt.

You can also get a GM, higher-output alt I hear works too.

Can't find the link to it at the moment.
 
If your current alternator is the old original I would prefer to change to the new built in voltage controller.
Replacing a broken bearing in an alternator is not very demanding, and it´s a cheap way to to solve your problem. So if your broken alternator is the built in type I would try to repair it first.
 
Rebuilding can be simple if it's just a crunchy bearing(s). Here's my DIY which is similar to yours except for the voltage regulator.

http://www.e9coupe.com/forum/showthread.php?t=21117

Pull it apart while documenting the steps and wiring etc, remove and measure the bearings and order some good quality 1st world ones, clean and reassemble. Buy a spare external regulator (or go ahead and replace now) because Murphy's Law says that will fail next.
 
internally regulated is simply more reliable

To give a blatant plug to my new book, "The Hack Mechanic's Guide to European Automotive Electrical Systems" (available for pre-order from www.bentleypublishers.com, use the coupon code "FriendOfRob" for 35% off list), I have a chapter about alternators, in which I say that an externally regulated alternator has three wires connecting the alternator and the regulator. That means three wires and six connectors (one at each end) that have the opportunity to fail. And on a 43 year old car, they WILL fail. Oil and heat will eventually get to them. And that's not even counting the old external mechanically-regulated alternator itself.

For these reasons, unless you're a total stickler for originality, the internally-regulated alternator is simply more reliable.

You'll need to connect the B+ terminal on the new alternator to the B+ wire in the old harness connector in order to get the alternator warning light to work, which you need to have working for the alternator to work. I just wrote about this in Roundel Online; see https://www.bmwcca.org/roundel/troubleshooting-alternator-warning-light

--Rob
 
This also depends on the quality of regulator. My 40 year old external regulator still worked when I converted to an internally regulated one. That regulator in the new alt failed within a year, upon removal I saw made in china. Replaced with Bosch Germany. I suppose the same goes for the external regulator replacement - buy the best you can find. The best chances of getting a quality regulator (and bearings) is to buy a new BMW alternator ($$$) not a rebuilt one from another company. If buying a rebuilt alt I'd source a new internal Bosch or other German regulator immediately if it came with a chinese one.


thehackmechanic said:
To give a blatant plug to my new book, "The Hack Mechanic's Guide to European Automotive Electrical Systems" (available for pre-order from www.bentleypublishers.com, use the coupon code "FriendOfRob" for 35% off list), I have a chapter about alternators, in which I say that an externally regulated alternator has three wires connecting the alternator and the regulator. That means three wires and six connectors (one at each end) that have the opportunity to fail. And on a 43 year old car, they WILL fail. Oil and heat will eventually get to them. And that's not even counting the old external mechanically-regulated alternator itself.

For these reasons, unless you're a total stickler for originality, the internally-regulated alternator is simply more reliable.

You'll need to connect the B+ terminal on the new alternator to the B+ wire in the old harness connector in order to get the alternator warning light to work, which you need to have working for the alternator to work. I just wrote about this in Roundel Online; see https://www.bmwcca.org/roundel/troubleshooting-alternator-warning-light

--Rob
Click to expand...
 
teahead said:
Where'd you get the v-belt pulley to put on there?

Wasn't quite clear on that post you provided (which I appreciate).
Click to expand...

It looks like a regular single groove v-belt pulley off an older 10SI alternator. It's about 2.6" in diameter. I have a couple of them in my garage.

You can buy one here:

http://www.aspwholesale.com/pulley-p2307.html


21-1100-1.jpg
 
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