Most refrigerator-freezers have a control that adjusts the operation of the cooling system of the freezer only. In such appliances, any control for the refrigerator is simply a mechanical system of opening or closing vents between the refrigerator and freezer to let in more or less cold air.
Before testing the control, unplug the refrigerator to avoid an electrical shock hazard.
Remove the temperature control dial or housing. Pull the dial straight away from the wall. Remove the temperature control. If there is a housing, it either snaps into place or is held in place with screws. Remove the screws, or gently depress the retaining clips with a small screwdriver. Allow the housing to hang by its wiring.