Whirlpool Stops Cooling

Hi All,
I have a Whirlpool fridge that stops cooling. All the lights are running and I can hear a fan going as well. If you adjust the temp controls to the coldest setting I will here the compressor kick on and it will start cooling again. However, over time it will stop cooling. Could this be a Start Capacitor/Overload or maybe the thermostat?

Thanks in advance?