I need to install an ignition warning light, pi am running a Nissan Micra alternator, so I need a simple diagram which will show how I may achieve the installation, can anyone help?

On most alternators the wire to the light is a earth when the alternator is not turning, then it goes live once it starts to turn.
so you have an ignition live to one side of the bulb, and your wire to alternator on the other side.

http://www.locostbuilders.co.uk/forum/8/viewthread.php?tid=39765