GM Genuine Parts HVAC Blower Motor Resistors are designed, engineered, and tested to rigorous standards, and are backed by General Motors. These HVAC blower motor resistors provide stepped voltage drops to provide multiple blower fan speeds. GM Genuine Parts are the true OE parts installed during the production of or validated by General Motors for GM vehicles. Some GM Genuine Parts may have formerly appeared as ACDelco GM Original Equipment (OE).