Thia ia a common problem with all window units. 1) The fan runs but no cold air is coming out. This indicates the compressor is not running. 2) The compressor is running and no air is coming out. The fan motor is not running. Both fan and compressor operate off the start-run capacitor, common to all window uunits
... Read more. This is located in the electrical control area of the air conditioner. note unplug the unit bdfore trying to locate this part. easily located, unplug the wires noting the color coded wires on which terminals, note make a diagram so you don't forget what wire goes on which terminal. Order and replace. If the unit is over 5 years old and you are able to afford to do so, I would replace the unit for a more efficent newer unit.
