The answer to 'central air blowing cold air' is that there are several common causes, including a refrigerant leak, a problem with the compressor, or a malfunctioning thermostat. Symptoms may include the air conditioner running constantly, the air not getting as cold as it should, or the system short-cycling (turning on and off rapidly).
Some potential solutions include checking the air filter, ensuring the outdoor unit is not blocked, and inspecting the refrigerant levels. However, many central air conditioning issues require the expertise of a professional HVAC technician, especially if the problem involves the compressor or refrigerant system.