We keep a compact, 2 year old, Frigidaire refrigerator (about 5 cubic feet) in our garage to use on those rare occasions that we need additional capacity (Parties, etc.) The fridge runs too cold and freezes what ever we put in there. I have it set on the warmest number but that doesn't make a difference. Do I need to replace the thermostat or temperature control? Are they one in the same? Is this easy to do for a novice?