The thermostat have nothing to do with the fans. The function of the thermostat is to open and close the valve to let thru or to stop the water to the engine.
Check the fuses, first of all, make sure all of them are in good shape.
If the fuses are OK, check the relays, sometimes some relays get stuck or damage.
Check the cables that goes to the fans. Unplug the cable and check for a pin out. If possible, check for voltage here.
And last, check the sensor. There is a sensor that when the car is at certain temperature, makes the fans turn on.
If everything above is OK, turn on the air conditioner, when it's on, both fans are suppose to work. If it still won't work, the fans need to be change.

Without looking up, the thermostat is always the end of the top radiator hose going to the engine top intake manifold or engine block. Usually a very easy fix. I do suggest to people all the time, to buy a Haines manual for their vehicle. Very cheap investment because they lay out everything for you to understand.