thermostat is located right outside the a/c evaporator core (a/c evaporator core is b/w blower motor and the heater core)
its a little piece i'd say about 3 X 1 X 1/2 inches. it has a 3 wire plug going into it.

oh yeah, another thing is that some times my a/c doesnt work as hard either. some times its super cold and sometimes it barely cools. i'm getting more freon put in pretty soon and i'll see what happens.

last year my a/c went out and it was the ecu that was bad. it didnt even threw a code.