KF48-1AS evaporator fan forces air in or out?

change the fan motor, if the fan dont wonrk wont spread cool air

Depends are you referring to the condenser fan or the evaporation fan? If it's the condenser fan you may have an issue with debris in the condenser coil not letting enough air flow to cool down so it will stay on to keep from burning up compressor.If it's inside the evaporator coil then it may be low on refrigerant possibly freezing up the evap coil making it run then kick into defrost run kick into defrost etc... hope this helps

Unplug the refrigerator and remove the contents of the freezer. Then remove air tower and the inside back panel inside the back of the freezer. Disconnect the evaporator fan and replace with the new fan motor. W10189703 Evaporator Fan Motor I am here if you have questionsm Thanks Sea Breeze

you machine has an electronic control instead of the old timers where you can manually advance the timer and out it in defrost. The part number 297282800 for it.
The first thing you want to do is open the freezer and see if the fan inside there is running. The reason is the freezer cools the refrigerator side by circulating air from the freezer. If the fan is running then your problem is one or more parts of the defrost system is malfunctioned and in return your problem arises. There are three parts to the system, the defrost timer or in some cases control board, defrost thermostat also known as a bi-metal, and the defrost heater. The defrost system is set up to operate as so. The defrost timer or control board will turn the machine off, in some cases every 8 hours, some 12. During this time period the defrost heaters, located behind the freezer wall and rest underneath the evaporator, yet wires to them run up the side of it, are energized and emit heat that raises upward to melt the ice that has formed on the evaporator coils. The bi-metal or defrost thermostat is at the top of the evaporator. When the heat from the heater starts to reach the bi-metal, it breaks the circuit turning the heater off. The whole purpose of this is because the freezer cool the refridgerator side by drawing air across the coils and blowing to the other side via the evap fan motor. In my opinion, if you change one part of the defrost system change them all because usually when one part fails another will follow, so save yourself the time and the food loss, the cost difference is minute.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/jason_4570d45317834dd3

http://beverage-air.com/pdf/manualsbycategory/K%20Series%20-%20Bottom%20Mount%20Reach-Ins/CFG_CRG_KF_Series809-046A.pdf

The fan has a limit control wired in series that shuts the fan down until the coil temperature reaches 25*F. this prevents the fan from blowing warm around after defrost.
There is also a switch which is placed for the door to close. Either one may be defective.
Worst case is the freezer is not pulling down temperature wise.

i could be wrong, but, look along the bottom of the door to see if the seal is tight to the frame......if there is an air gap it is causing the floor to freeze the cold air....

On a top-freezer when the drain stops up water will back up turning to ice and eventually filling the air ducks with ice blocking airflow to the fresh food section causing it not to cool. You will also see a water leak inside the fresh food section. To fix this, remove the evaporator cover, (back or bottom of freezer) and then remove all the ice. Once all the ice is removed, you need to unclog the drain. I do this by forcing hot water down the drain with a turkey baser but you can use any squirt bottle, I have even used the water hose. Once the drain is clear, mix water and baking soda and pour it down the drain to prevent this from happening again anytime soon.

Defrost problem.

The evaporator fan should be pulling air from the freezer over the evaporator and directing the air down into the frig and circulating through out the freezer.
Hope this helps.

There are three main reasons the fans would not come on.
1: A bad door switch. There are switches on the top part of door frame. They turn fans off when door is opened to prevent warm air from being drawn into unit when door is open. If a switch goes bad the fans will never turn on.
2: Refrigeration problem. The fans are tied into a temperature switch called a fan delay. The fans will not come on until the coil is well below freezing. This is to prevent water spray after a defrost. If unit is low on gas or has any other cooling issue the fans will not come on.
3: Bad fan delay switch. If the fan delay switch becomes "stuck open" the fans will not be energized.

Feel the back of your evaporator coil, if it is very cold and frosted you probably have a bad fan switch, or a bad door switch. ;)