Blower Motor Resistors Direct OE replacements for these critical interior heating and AC system components Responsible for changing blower motor speed in response to dash control movement Exact OE connectors and terminals made of premium materials for easy connexion to the vehicle 185 Numbers in stock North American market Coverage Find a retailer The Blower Motor Resistor is an electrical component that is a part of the vehicle’s interior heating and air-conditioning system. It is responsible for controlling the blower motor’s fan speed. When the fan speed is changed via the dash controls, the blower motor resistor changes the speed of the blower motor. A failed blower motor resistor can cause issues with the operation of the entire heating and air-conditioning system. Usually, a bad or failing blower motor resistor will produce a few symptoms that can alert the driver of a potential issue.