There might be a switch like that somewhere. Like I said, I never had to work on the AC on my 97 2GNT. There's subtle differences between them, as the 95s (maybe 96s, too) had the 2-stage AC switch. 97-on had a 1-click AC button (green only).

If it's never worked, I'd suggest getting the factory service manual (search for it, it's around and free) and looking up which pins on the compressor connection are for the clutch.

If the clutch works, then it's likely the system has lost its charge. You can spend less than $20 getting all new o-rings for the lines from the dealer, get everything back together nice and neat, then see if you can't talk the local AC shop into taking a $20 to pull a vacuum on the system to check for leaks for you.

Then just have them charge the system and enjoy your AC this winter! (The compressor plays a role in the defroster actually de-fogging the windows, mind you.)