Mk1 1.1 -> 1.6Diesel Conversion - Adding Glow Plug Relay

Hi,
    I've almost finished my conversion and it has gone reasonably well.
However I'd like to add a glow plug relay to get things going in the cold.
I got a timer relay box from another car that runs the plugs for so long after it detects the starter signal but the relay itself is burned out and I have to press in manually to fire the plugs at the moment

I have the full loom and fuse box from the original diesel donor and I was wondering if the petrol fuse box has the socket for the glow plug relay and if so which one is it?

Also my battery light doesnt turn on when I turn the ignition to the run position and the coil in the alternator isnt energised so it isnt charging. There are three wires to the alternator, as far as I know one is +12v for excitation, one is +12v for charging the battery and the other is the 0v connection (the small one).
How do I need to wire it up so that it charges?
I tried wiring both the large terminals direct to the battery (thinking that this would work even though it would run down the battery when the car was off) but it doesnt charge this way either.
I've changed the regulator / brushes over from another alternator as I originally thought this was the problem (the brushes were a bit short).

Thanks in advance for your replies.