MG Car Repair: Alternator, moss europe, moss motors

Question
I have a 1977 MGB I ordered the wrong Alternator thinking my mgb was a 1979. Before I realized the error the new alternator was installed. The 1977 is a Small/Large/Small plug and the 1979 is a Large/Large/Small. Will this conversion be ok to use? The  car starts and runs but there is one wire that is no longer connected to the alternator. It is a small brown wire. The large Brown and Brown/yellow are attatched. I am trying to restore this to like new quality and if I need to purchase a new alternator and connecting kit I will do that and take the loss because I made the error. Thank you. I'm learning.

Answer
Hi Don.  You have bought the wrong alternator for your car.  The simplest thing to do is to return it in exchange for the correct one.  You need the 18ACR alternator type GEU2213 which was only fitted for a couple of years.  

If you want to fit the alternator that you have bought, then you will have to cut the special plug off the wiring loom and fit a different set of ends.  (I think you may have already done this).  You will need 2 large female Lucar connectors and one small one.  The small one takes the Brown/Yellow wire.  The other two wires are plain brown, one thicker than the other.  These plug into the two large terminals inside the alternator.  They are interchangeable, because they are connected together inside the alternator.  If you look inside the back of the alternator you can see where they are joined together.  

There is a special conversion socket that you can buy which is much better than 3 separate terminals.  It is available from Moss Motors, part number GEU250.   It is part number 12 in this diagram:   

http://www.moss-europe.co.uk/Shop/ViewProducts.aspx?PlateIndexID=12694&SortOrder...

The price is only about $6.00 and it would be much safer to use this.  There would be less risk of an electrical fire.