Possible causes from top of my mind:
lack of freon;
bad cycle switch;
bad high pressure cutoff switch;
bad compressor clutch;
bad clutch energizing relay;
blend door actuator;
vacuum line to actuator (if actuator in 97 is pneumatic, I am more familiar with 93);
climate control unit;
and definitely something I forgot.
Generally speaking, there is no rocket science in car A/C system (especially in 97 Taurus), and all analysis could be done with gauges manifold and multimeter, but you should exactly know what you are doing.