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MG MGB Technical - Alternator

I think the alternator on my 1977 BGT has packed up

Symptoms were ignition light not coming on at all, then flickering at idle, then sometimes comin on as normal. After a long journey, most at night with full beam on the next day the battery was totally dead and alternastor just buzzes when ignition is turned.

I was looking on Moss online and other sources for the alternator and saw that there is an alternator for pre 1978 BGT's and one for 78 owards. However there seems to be a massive price difference between the two, the pre 78 part being double the price.

My questions are:
Can a post 78 alternator be fitted in a 77 BGT?
What's the general cost of getting an alternator repaired/rewound?
Can you re-use the pulley and fan from the old alternator?


J Fletcher

Have you tried Halfords? I used them for my replacement. Not very expensive. You usually re-use the pulley/fan - so take them off first as Hlafords will want the old unit in exchange.

T Crossley


I just went to Halfords and it was 97 for an alternator and a 62 surcharge if the old unit is not exchanged in full! I was quite surprised but maybe they are tightening up on this.

J Fletcher

I'd try one of the other mg specialists like Octarine Services, the Welsh MG Centre, or MG Owners Club to mention but a fewe. Last alternator I had (2002) was about 35 for a '74 car.
Steve Postins


Are you sure Halfords quoted you for the correct alternator, or for a new one?

A couple of months ago I needed a replacement for my 1976 MGBGT alternator.

I went to Halfords first, who quoted about 36 for a recondishoned exchange unit (an extra 12 if you didnt have the old unit). They ordered it, but when it arrived the casing was broken so I told them to forget it.

I got mine from MGBHive(I can drive there), which at the time was about the same price, although I believe they have stopped doing exchange as the cost of return postage/carriage is as much as the old unit is worth.

I think their outright price is about 50 now. Give them a ring.

I believe that the Lucas 18 ACR was used through from 69 to 81, although some 69-74 roadsters had the Lucas 16 ACR, and 75-78 had a different connection (like mine) but a cheap kit replaces this.

Robert Brandreth

Blimey james, I got one (for an 1970 car) earlier this year and it was less than 40quid.
I wonder if they knew what you meant? A few weeks ago I tried to order something and they went through the computer:

Him:"What sort of car is it"
Him:"Are those the green ones?"
Me:"Erm....they came in several colours...."
Him:"You know what I mean..."

Turns out he was asking if it was like the the BTCC cars (MGZS) -which are not green anyway!

might be worth trying again, but asking for the guy in the back old enough to grow whiskers on his chin :-)

T Crossley

There are a number of options - basically all Lucas 16/17/18 ACR units will fit - even if you have to rotate the front cover. So will some Bosch units fitted to Fords - but only the ones with three through bolts.

GEU 213E is an 18 ACR recon unit at 51 + exchange deposit of 47

GEU 206 is a NEW 65 amp 18 ACR at 60

GEU 216 is a NEW 65 amp 16/17 ACR at 42

Anyone want more info - e-mail me.
Chris at Octarine Services


Yes exactly! If I had asked if he could supply me some low profile alloys or a bass bin then his ears would have pricked up.

Anyway going to try a bigger halfords nearer my home and find someone over 17!

J Fletcher

my alternator died on my car and after ringing round a few places I got it rebuilt by a local Auto-Electrical firm, cost 27 to have it fully rebuilt in a day (the only thing original is the black plastic casing on the outside - Marina Alternator ;)).

Try the yellow pages ( for Auto Electricians, one of them will come up trumps!
Stefan Carlton 1

My last one for a 72 c/b car 17ACR Lucas LRA100 was 22.66 + vat in 2002. That was from LS UK (Lucas Service) 18 ACR is not very much more.
iain mackintosh

You guys are lucky. Rebuilding a Lucas over here costs a $mall fortune. For that very reason I modified a Delco (GM) alternator and have been happy ever since.
$12 USD for the chrome "J" bracket (oooh) made the cost $22 USD total.


This thread was discussed between 13/09/2004 and 16/09/2004

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