Driver's side seat won't move

You don't need to go to the dealer. They will just charge you $1200 and replace your seat. All you need to do is replace your seat gear. Here is the link with photos on how to repair it. http://www.odometergears.com/documentation/Infiniti_Nissan_FAQ_Seat_Gear_Replacement.pdf

You may be hearing the motor or a relay clicking, but either way it will need to be looked at by someone that has the computer to connect to the seat control module so they can see what is going on here. It sounds like the switch is OK, but it's possible the motor or wiring is the problem. One thing you can do is look under the seat and make sure there's nothing jammed under there causing this, or something could have accidentally disconnected the wiring to the motor. Here are some shops I would call if you need a place to look at this: http://repairpal.com/infiniti-repair-in-philadelphia-pennsylvania