Why wont my 93 infiniti g20 start and the battery is new and nothing on the dash turns on?

We are having that problem with our 1999 G20t. My honey first had the alternator and battery checked (he removed them ad took them to Advanced Auto). Those were in great shape. We were told it could be the ignition starter switch or starter fuse. Those two parts are only available at the dealership and not too expensive if you can replace it yourself. We are looking fro pictures on the net that might show us were those are located in the car. Hope that works a little.

cris