* The Heater Control Panel: This is the dial or buttons inside the vehicle that you use to adjust the temperature, fan speed, and air direction (e.g., vents, defrost). This panel sends electrical signals to other components.
* The Blend Door Actuator: This is a small motor that controls the mix of hot and cold air. It's located inside the dashboard and is responsible for the temperature setting you select on the control panel. A faulty blend door actuator is a common cause of heating problems.
* The Heater Core: This is a small radiator located inside the vehicle's heating and air conditioning system. Hot coolant from the engine flows through it, and a fan blows air over it to warm the air that's sent into the cabin.
* The Blower Motor: This motor is what forces the air through the heater core and out the vents. It's controlled by the fan speed setting on your control panel.
* The Control Module (possibly): Depending on the exact specifications of your vehicle and its options, there might be a separate control module that receives signals from the control panel and sends commands to the actuators and blower motor. This is less likely to be the primary control component itself than the other listed items.
If your heater isn't working, the problem could be in any of these components. Start by checking the fuses for the heater system (consult your owner's manual) and then suspect the control panel, blend door actuator, blower motor resistor (common point of failure), and blower motor itself in that order. A faulty heater core is less common to cause a complete lack of heat as a leak would be more of a problem.
