96 V6/5 speed with 104,000 miles, A/C stopped working on the highway yesterday and the temp gauge was almost pegged. Let it cool off for a while, temp was below "normal", tried driving a little bit after checking the coolant level (which was good) and couldnt see any noticable problems under the hood (belt was fine and stuff) Had to get the car towed home, replaced the thermostat today and still no luck. What can this be? Thanks!