1996 Chrysler Concorde oveheating

Engine Cooling problem
1996 Chrysler Concorde 6 cyl Automatic

i replaced the water pump and timing belt. The car drove ok the first time I tried it but now it overheats do I need to recheck the timng. I already replaced the thermostat, the fan runs at first but it stops running. I tried turning the ac on and the fan runs ok.