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MG MGB Technical - bosch alternator help!

I need help! I just fried my second Delco alternator and want to switch to the Bosch. I found a part number of 13107 in the archives, but what are the details of this part, and where I can get it for under $180? Is the 55 amp Ford unit the way to go, or will almost any Bosch fit?
Thanks in advance!
Jeff Schlemmer

Do you need that big of an alternator? If not, check out the Suzuki Samurai alternator.
Leland Bradley

I might add that I have NO electric fan, blower motor, radio, etc... I just need a reliable alternator to replace my second (used) Saturn unit.
Maybe I should buy a new/rebuilt Saturn? But I don't need 96 amps!
Jeff Schlemmer

Jeff:
NAPA has these under catalog number #BA1860137 for $109.00 each, core of $5.00
I've had mine five years and love it!

Peter
Peter Van Syckle

Thanks Peter. Which application is that unit? How many amps?
Thanks.
Jeff Schlemmer

Hi, Jeff:

You said, "Maybe I should buy a new/rebuilt Saturn? But I don't need 96 amps!"

If you DO decide to get a Saturn, the Advance Parts part number is P81073. I just put one in my 69 MGB and love it. It's not a simple "plug & play" swap but the alterations are doable. Here's a link to my write-up:

http://web.ics.purdue.edu/~fishertr/alternator.html
Tom Fisher

Jeff:

It's the 1980 Ford Fiesta Bosch unit that Bob Munch references in his article. I beleive it's 55 amps, which is plenty of power. You'll need a longer fan belt (1") .
NAPA gets these out of their main warehouse in Atlanta, so it may take a day or two.They refer to the core as a 'Heritage Core', meaning they're keen to get it back! Check out www.napaonline.com. You'd be suprised how many parts they have for our cars.

Others have used alternative supplirs, like Checkers and RockAuto. I've always done well with NAPA.

Peter
Peter Van Syckle

Thank you all for the fast help! The link for Bob's website seems to be dead or moved. Does the Bosch alternator require an electrical adapter like the Saturn unit? I suppose the nice guys at Napa will let me open the box to find out, but if you know a part number, that would be great.
Thanks again!!!
Jeff Schlemmer

Jeff:

Mine was a straight plug-in deal- no new plug needed.
Here's Bob's website on the subject.

http://www.cibolas7.net/17901.html

Good luck

Peter
Peter Van Syckle

Jeff,
If you have just about any alternator excitor wire hooked direct to power rather then running it through a resistor or dummy light on the dashboard, it may have a tendency to burn out. Something to do with the alternator only able to take a very small amount of amps through there according to what i have seen. This might help your issue instead of going to the older Bosch.

-BMC.
BMC Brian McCullough

Jeff,

it is easy to pick a cheap 55 Amps Bosch at a breakers yard.If not crashed, ther should be no problem with the bearing, thy never seems to fail. For a check up remove the small regulater/bushes holder on the back and check the length of the bushes incorporated in the regulator.
You get access to them by undoing the two screws, there are no tricks to follow!
These regulater/bushes spares are interchargable from most Bosch alternaters, BMW, Mercedes, VW...
I run this type of alternaters on both MGB since the 80's and only changed the regulater once.
According 35 / 55 Amps, the 55 Amps version also charges very well with all the lights on, heated rear window on the GT, heater and whipers, while the smaller one would be at its limits.
Take one with a 3 pole plug and a short rest of the wires! Connect the big brown one to the big red one, both other connectors are bridged internaly and you can add the small diam. wires to them.

Ralph
Ralph

If you're running a high-amperage alternator (I'm using a 105-amp Saturn unit), do remember that the existing brown wire is not up to carrying that current back to the solonoid. A #10 lead would be better. Lacking any #10 wire, I ran two additional #12s. I got mine from Advance Auto for about $90 with a lifetime warrenty to the original purchaser. It's worked fine for its first year, but my more recent experience with an Advance Auto rebuilt wiper motor has rather diminished my confidence in their products. It was nicely painted, but rusted and seized inside.

But if you don't have any special electrical demands, why not a good old Lucas? I think the 18ACR fitted to the late cars was quite a bit upgraded from the 16ACR (I'm not sure about the numbers) fitted during the early '70s and Ive had wonderful experience with these.

FWIW,
Allen
Allen Bachelder

The Ford Fiesta Bosch Alt. conversion was originally done to cure an ill of the earliest Lucas Alternators, the 16AC (separate voltage regulator) and its later brother, the 16ACR (built in voltage regulator), both of which "suffered" from too high rpms for alternator cut-in (activation) for good service in some idle situtions. Had we been a tad more knowledgable about the alternator choices available, we could have simply replaced those old turds with an 18ACR and been done with it.

All the alternator conversions I have ever seen done do more to prove that just about any make of alternator can be chosen and do the job effectively, which is, in the end, all that an automotive electrical engineer does when he chooses OE units. He picks from his car company's affiliated (and bean counter friendly) range of units and our batteries get charged.

The main advantage a Bosch has over a Delco or a Mitsubishi or a Hitachi or whatever, is that it duplicates the mounting pattern of the OE Lucas, obviating mounting related problems (and some truly are problems ~ broken water pump mounting lugs being a common example) that units requiring modifications can run into. I am not convinced at this point that any of the conversions offered is a truly significantly better choice than the Lucas 18ACR or one of its higher output siblings. If you read my site, you will see that I tried to make this point a long time ago.
Bob Muenchausen

I agree with Bob about the 18ACR, but due to a number of higher-demand additions to my car (A/C and attendant dual radiator/condenser fans, halogen headlights, etc.) I needed more amps. The Saturn/Delco 105-amp unit not only provides much more than enough amps, it's very easy to install as the brackets can be realigned to fit the Lucas mountings perfectly. See Darryl McLendon's excellent instructions on this at http://mg-abc.com/docs/alternator.htm. As he shows, rotating the front piece creates a mounting pattern identical to the Lucas, making for a straight-forward bolt-on installation.

FWIW,
Allen
Allen Bachelder

You can get the Bosch replacement alternator at local chain autoparts stores for around $50-.

Kragen Auto Parts (chain goes by different names in different parts of the country)

<http://www.partsamerica.com/ProductList.aspx?parttype=11&searchfor=Alternator&ptset=A>

Part No.
13107 Worldwide Imp ALTERNATOR
Reman; with Bosch Alternator; 55 Amps; Warranty: Lifetime Replacement Warranty

Ships in 1 day
$49.99 $18.00 core






Kimberly

Allen.

I have the Delco 96 amp and it bolts right up. Only two wires to connect and it is over. I also have the halogen lights, plus with everything else on this unit is more than capable of handling it.

I had the Moss Alternator with the Supercharger (brand new), and it did not last 2 weeks and the bearings were shot. This Delco 96amp has not had a problem and for under $100 you cant go wrong. E-Bay

The good point is if you want to add some other item this unit has the amps to do it. Same as yours.

The #10 wire is a good suggestion.

Ray
Ray 1977mgb

Bob's right, of course. The rebuilt 18ACR alternator is a bit pricey, though. NAPA# RAY139381 at $209.00, plus core.

Peter
Peter VanSyckle

Wow! This thread never seems to fail to resurrect a LOT of good, informative help!

I must go with the Bosch this time. The Lucas 16 ACR failed me (with 55k miles on it) and two Saturn 96A units have failed me. Next time I'll go with the 18ACR, or something new and unexplored!

Brian, I followed the wiring diagrams on all the posted web pages and have an alternator "dummy" light, so is there another wiring trick I missed?

Thanks all!
Jeff Schlemmer

Sometimes an alternator may not need complete replacement.

Some years ago I broke an 18ACR that a friend had lent me from his Rover 2000. I got the polarity wrong when charging a very flat battery!!

The regulator section under the back cover had been damaged. I was able to by that section on its own quite cheaply and solder it in. If you have an alternator that is still mechanically sound but has stopped charging this may be worth a try. My local Lucas agent had the parts on the shelf.
David Witham

I sure like my Bosch conversion. From Central Auto Parts, [used] $12
SF
Dwight
DCM McCullough

Daryl's original site, http://www.onefastmgb.com/pages/6/index.htm , is also linked from my own for the reasons others have cited above. The Delco/Bosch unit he recommends at his site is little more than a higher output (and a bit more modern) version of the same basic Bosch Alternator used for the Ford Fiesta.

I still run on my original Fiesta Bosch alternator and it has performed well enough that I credit it with maintaining my Diehard Grp 26 battery (not the best battery around even when new) well enough over time (since 1998) to allow that battery to function very well even today. That is not a bad record, and the main function of any make is to do the same. If you have need for lots of amps, the later Saturn/Delco/Bosch unit Daryl recommends is a very good and safe choice.

I may replace the Fiesta unit when it dies with another, or simply replace it with an 18ACR or one of Daryl's. From what I have seen and been informed about (from folks like Dan Masters and Rick Astley) indicates that these are probably the best choices out there.
Bob Muenchausen

This thread was discussed between 13/06/2006 and 15/06/2006

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