The blower motor is part of your vehicle’s heating, ventilation, and air conditioning (HVAC) system. The blower is an electrical fan assembly mounted in the HVAC ducts below the dashboard ahead of the glove box.
Whenever you operate the vent, heat, or air conditioner, the blower motor forces air through the vents at one of a number of speed settings. When you select a fan speed, a resistor in the electrical pathway of the blower motor alters the amount of electrical current flowing to the blower motor in response to your selection.
In combination with another device, the blend door, the blower motor is able to bring air of different temperatures into the cabin. When you choose the heat setting, the blower motor sends air across the hot heater core in the system. If you choose cool air from the air conditioner, the blend door changes the path of the air flow and allows it to pass over the cold evaporator instead.
When a blower motor fails, one of two problems occur. In one case, the air coming from the vents, warm or cool, does not come out with any force. The heater might still work, and the air conditioner might still cool, but the pressure from the vents is significantly reduced. Regardless of what fan speed setting you select, the air simply does not blow from the vents. In this case, the fan motor might be faulty.
In the other case, the fan refuses to work on one or more of its speed settings. For instance, it might blow when you select the highest speed setting, but not on lower settings. This would indicate that the resistor might be bad.
Problems with air flow can also point to other issues, such as a bad relay, blown fuse, or even a clogged cabin air filter.
Due to its location underneath the dashboard and ahead of the glove box, it is necessary for a technician to access the inside of your vehicle for blower motor replacement. The glove box must be removed and lower dash components disassembled. From there, a technician will take the following general steps to remove the blower motor housing and replace the blower motor: