In most refrigerator freezers, the refrigerator gets its cold from the freezer. The evaporator fan circulates air over the coils in the freezer and cold air circulates into the refrigerator through vents. If the vents are blocked or closed, then the fridge will not get cold enough but the freezer will. If neither is cold enough, then the number of possibilities increases.
Lowering the freezer temperature will increase the cooling cycle activity. Setting the refrigerator temperature may have little affect on the cooling cycles because it simply changes the vent opening size. Decreasing the fridge temperature opens the vents more and increases air circulation from the freezer.
The temperature can be adjusted using the controls found inside the refrigerator or freezer. The ideal freezer temperature is about 0 to 5 degrees (F) and about 38 degrees (F) for the fridge.
Measure the temperature by placing a cup of alcohol or cooking oil with a cooking thermometer into the freezer for about 2 hours. The oil or alcohol will not freeze and make it possible to accurately measure the temperature. If you used water, it would freeze and the thermometer would not display the correct reading. Also, the freezing water may damage a thermometer placed in it.