Freezer doesn't get cold enough

here is how it works all friges are just freezers . there is a fan which blows cold air from the freezer to the fridge. yes defrost it all and take notice of the fan and duct to the fridge. allso clean the fins and under carrage the compresser fan draws iun dirt and dust and doesnt work right. it might need a burst of freon or what ever there useing in your state

pressure on your system is low may needs service or clean the condenser located on the back of the fridge that may help if not add some more gas to compensate the pressure