heater in my car blow the cold air?

Is there coolant in the expansion tank. Is the radiator hoses warm after the car has been running? If the engine is running at the appropriate temperature then your blend door or actuator or even your heater control valve are not working. Can you hear the blend door moving when you change the inside temperatures? The heater control valve is located on the firewall in the engine compartment. When you select warm or cold make sure the valve is opening and closing. When it should be warm the rubber hoses should both be warm. If they are not then I would replace that valve. It cost about $80.00 from the dealer and takes about 1.5 hours and some coolant. Good luck.

check for bad vale and car get hot. check heater core . it my be plug