Model: 253-54743301 Kenmore Refrigerator\r\nlost cooling in both Refrigerator and Freezer

Cut everything off for a few minutes then turn it back on and listen for a click from the compressor relay as the compressor tries to start.
Is the compressor motor running.If no check starter/overload relay. The relay is a small usually black cube shaped electrical part plugged into the compressor or wired to it nearby. It may appear burnt or rattle when shaken if it's bad. The two connections should show continuity with an amp meter. If it's good then it's most likely the compressor causing the problem.
Check to see if the condenser fan at the back underneath near the compressor is running. If no check fan.

Are the condenser coils near there warm or room temp. should be warm





Is the evaporator fan in the freezer running. It blows cold air into the fridge side through a damper in the wall between the freezer and fridge. Make sure the damper is open.

Below the evaporator fan is the evaporator coils. Remove the back cover in the freezer to observe the frost pattern. Light frost everywhere(NORMAL) or a partial pattern of ice(LOW ON FREON) or nothing(LOW FREON OR COMPRESSOR PROBLEM).
If it's iced up really heavy you have an auto defrost problem. Melt the ice with a hairdryer and check the defrost system.