Bought 4 small Gold Star units in 2009. One quit cooling altogether, one blows slightly cool while the longer another stays on the less it cools. One did not cool well when it was new. All filters are in good shape.

Http://www.appliancepartspros.com/partsearch/frame_diagram.aspx?diagram_id=28700000&pkw_=basket&model_id=5520000&NewWindow=1

Download this illustration and then using a good multimeter start basic troubleshooting.


All residential window air conditioners have a cooling system made up of four primary components, a compressor, an evaporator fan, a control or switch, capacitor.When the thermostat is calling for a colder room temperature the compressor is energized. It is normally very quiet. The evaporator is always located on the front of the air conditioner. It also has silver fins. Be sure it is clean. Use a foaming type cleaner and rinse with plain water. Because the evaporator is absorbing heat, it is very cold to the touch. The temperature drop causes any humidity in the air to collect on the evaporator - sometimes called sweat. There is a fan inside the air conditioner that circulates the air for the evaporator and condenser coils. The circulating fan and compressor are running simultaneously. The fan motor has two fan blades attached to it on either end. The fan blade on the inside part of the unit continually draws room air over the evaporator coils, which are cold. The fan blade on the outside part of the unit continually draws fresh outside air over the condenser coils, which are warm. Because the evaporator coils are cold, they cause moisture in the room to collect on them, much like a cup of ice water on a warm, humid day. When the amount of moisture increases, it begins to drip down off of the coils into the bottom pan of the air conditioner.
If the compressor fails to start or the fan you may need to replace the capacitor.
You may need a hard start kit.



Thermostat control The thermostat on a window air conditioner works by sensing the air temperature entering the air conditioner. As the air entering the unit reaches the set temperature it will cause the compressor to turn off. The blower may continue to run depending on the selection chosen on the control panel. Digital thermostats work on a similar principle but display a more precise temperature.
Test for continuity with the multimeter between the two terminals . Warm you should read continuity (contacts closed). If not change it.
Selector switches The air conditioner selector switches allow the user to choose the fan speed. The compressor always runs at the same speed regardless of the settings. If low cool is chosen, for example, the fan runs at a slower speed but the compressor still offers the same cooling capacity. There are other switches to control louver operation and other features on some units.