you need to replace your heater core
Low coolant, failed thermostat, partially plugged heater core...............
Only blows cold air with the a/c on while driving, your cooling fan or fan clutch is bad depending on the year, make and model.......... Only blows cold air with the heater on while driving, you will have a bad or broken internal a/c - heater control door.....
Low on coolant. Stuck open thermostat. Poor circulation (plugged heater core).
Poor circulation probably due to a restricted (plugged up) heater core.
It is either your water pump or your thermostat
When a vehicle is idling, the engine may not produce enough heat to warm the coolant effectively, leading to cold air from the heater. In contrast, while driving, the engine works harder and generates more heat, allowing the heater to blow warm air. The engine temperature can rise while idling due to reduced airflow through the radiator and less coolant circulation, while driving increases airflow and coolant flow, helping to cool the engine.
Well it should blow cold while driving and stopped. You probably need to get your AC recharged. Hope I helped!!
thermostat probably damaged or stuck....and worse case scenario....your heater core is going out.
Your heater will blow cold air only.
It doesn't really blow it out it just warms the cold air.
it wont blow heat itll blow cold air
cool hello