Ignition problem - wiring diagram

[blessedin84]

I'm a new owner of a 1990 300ZX, 5-speed, non-turbo. Right off the bat I had to replace the alternator. Now, the car continues to run after I cut the ignition off and take the key out. I'm not talking dieseling; I talking running like driving it away. Nobody can seem to agree on what the problem is because nobody, (including the local Nissan dealer's parts department) can agree on what parts are within the ignition system. Is there an electric ignition module behind the key, behind the dash or none at all? Is there an ignition relay somewhere? If so, where? If anyone has had this probem before and can tell me what solved their problem, it would be appreciated. A wiring diagram of the ignition or schematic of the whole car would be really appreciated. I am in the process of ordering everything I may need down the line but could use these things now so I can get this car back on the road. Attachments can be emailed to [email protected]. Thanks to all.