- Heater core: The heater core is a small radiator located behind the dashboard that helps transfer the engine's heat into the cabin. If the heater core becomes blocked or damaged, it will not be able to transfer the heat effectively, resulting in a lack of warm air inside your vehicle.
- Cooling system issues: If your vehicle's cooling system is not functioning properly, it may not be able to provide sufficient heat to the heater core. Common cooling system issues that can lead to a lack of heat include low coolant levels, a faulty thermostat, or a malfunctioning water pump.
- Blend door: The blend door is a small flap that regulates the airflow from the heater core and the outside air into the cabin. If the blend door becomes stuck or damaged, it will not be able to properly mix the heated air with the outside air, resulting in a lack of heat inside the vehicle.
- Blower motor: The blower motor is responsible for circulating the heated air inside the vehicle. If the blower motor fails or is damaged, it will not be able to circulate the warm air, resulting in a lack of heat inside the cabin.
- Electrical issues: If there are electrical problems with the heater controls, such as a blown fuse or a faulty relay, it can also prevent the heater from working properly.
If you suspect that your Blazer's heat is not working due to one of these reasons, it is recommended that you have the vehicle inspected and repaired by a qualified mechanic.
