A heater can stop working for a number of reasons, including: These instructions will help you diagnose and fix a car heating system that blows cold air. Car Ac Basics Cooling Unit Car Basic Heater not working correctly i have a 2012 dodge avenger se 4 cylinder. Car heater not working properly . When your vehicle’s engine has cooled down, open the radiator cap and check the level of coolant. There are internal flaps in the system to direct air up for defrost. If the thermostat is bad, it could mean that it is not efficiently regulating the temperature of the coolant for the heater. Videos you watch may be added to the tv's watch history and. It’s freezing outside, and all you want is to get in your car and turn on the heat. Maybe the fan is malfunctioning. If you can't hear it move, you may be looking at an issue with the thermostat switch (if your car has one); Here are a few of the more common reasons that’s causing the car heater to not work properly: ...