MG Car Repair: Fuse #3 Circuit, overdrive switch, instrument failure

Question
Hi Brian,
Ron had posted a question to Barrie 8/16 (http://en.allexperts.com/q/MG-Car-Repair-3786/2011/8/instrument-failure.htm) which I am having exactly the same problem.

It appears the white wire feeding into fuse #3 is not being energized.  If I disconnect the fuse, and feed the opposite end power, everything works great.  When I feed the white wire power, I am getting a power draw (noticeable sparking).  I am assuming this is the case because that white wire also leads to the fuel pump.

I just installed a new Alternator, everything seemed to be working fine.  Also, everything was working fine until a friend of mine hit the overdrive switch which I heard a clack sound.  I don't know if that had anything to do with it, but that is the only defining moment I can think of happening between when it worked and when it stopped working.

I have been studying the electrical diagram, it seems to be a straight line from the ignition switch except for the splitter, where it splits the current to the fuel pump and the fuse box.  Where is that splitter?

Thank you for any insight you might have.

Answer
Hi Joe - sorry for my delay in response. I was away on vacation and haven't checked e-mails for awhile. Anyway.  Fuse #3 and the white wire. I don't believe you mentioned the model of MG you're looking at, but I'll assume an early MGB for this purpose. There are three white wires off of #3 - one to the fuel pump, one to the ignition coil, and one to the ignition switch. The splitter as you call it, is a rubber plug in connector and the only way I believe you can find it is to trace the wire(s).  I can't tell you exactly where it is. I suppose I need to read the earlier posting of Barrie to which you referred to find out what your problem is as you say you are having exactly the same one.  Give me a bit more time, and I may be able to help you sort this out.  I'll review the Barrie 8/16 answer.  Thanks, and sorry I can't be more help at this time.   Brian

Follow up ---------
I have reviewed Barrie Jones answer as referenced above and find we are talking about an 80 MGB. Alas, I have no more to add. Just remember, wires themselves rarely fail, components attached to the wires sometimes do. If it were me, I'd start with the ignition switch.

Thanks,
Brian