I have a 2002 civic and the A/C light on the switch will not go off, when it's on defrost or defrost/floor I get heat other then that it's cold air. Is this a simple switch or more?

 

There is a small computer in the main control panel that controls everything. (The little set of 3 buttons is just buttons and lights that go in and out of the computer in the part with the dials.) Try disconnecting the battery with the key off to reset all the computers in the car. If you still have the stock radio, be sure you know the security code first, as disconnecting the battery will put the radio in lockout mode.

If it still does the same thing, you can run a self-test on the control panel and air control system using the procedure in the service manual (download it).