The Heater Blower Control Module is part of the car heating and air conditioning system. We have 3 associated problem symptoms connected to it.
When the heating or air conditioning is switched on there's no air coming through the heater vents and no sound that you normally hear when the heating is on.
When the heating is turned on the amount of air coming through them is low regardless of the heater setting.
The fan speed for the heater cannot be adjusted using the controls, it stays on the same setting regardless of the controls.