My passenger window on my 93 Civic goes up and down with the drivers side switch but the passenger switch doesn't work at all. What will be the problem? Do I only need a switch?

 

Since it works from your driver side its going to be either the switch or the wiring. Check your underdash fuses and make sure its good, if they are, you can take of the panel and test the leads on the wiring, if they have power you know its your switch.