I replaced my a/c belt on my 1999 intrepid and afterwards trying out the a/c function. I noticed that the fan blades aren't turning. Nothing electronic was touched and all fuses are good. Do you think that it could be the thermostat?

Assuming that you are speaking of the radiator fans, they don't normally come on until the engine warms up. If the car was not overheating before the A/C belt belt was replaced, then the fans were working. Start the engine and feel the radiator where the upper engine radiator hose fits. When the thermostat opens, the radiator will suddenly get hot. The fans should come on shortly after that. Check the temperature sensor near where the upper hose comes off of the engine--there should be a wire attached to it. Does the temp gauge move normally?