The AC Blower Motor Resistor controls the fan speed in your AC and heating system. If you can no longer adjust the air speed with your AC controls or your AC system no longer blows chances are you need a new Blower Motor Resistor. Fits the following models with Auto AC controls or with 1st design modules labeled 52413530 OR 52409643: 2004-2006 Rainier 2003-2006 Escalade including ESV & EXT 2003-2006 Avalanche 1500, 2500 2003-2006 SSR 2003-2006 Silverado 1500 2003, 2005-2006 Silverado 1500 HD 2003-2004 Silverado 2500 2003-2006 Silverado 2500 HD 2003-2006 Silverado 3500 2003-2006 Suburban 1500, 2500 2003-2006 Tahoe 2003-2006 Trailblazer including EXT 2003-2006 Envoy including Envoy XL 2004-2005 Envoy XUV 2003-2006 Sierra 1500 2003, 2005-2006 Sierra 1500 HD 2003-2004 Sierra 2500 2003-2006 Sierra 2500 HD 2003-2006 Sierra 3500 2003-2006 Yukon, Yukon XL 1500, Yukon XL 2500 2003-2006 Isuzu Ascender 2003-2004 Bravada 2005-2006 Saab 9-7x Replaces part numbers: 1580567, 93803636, 52413530, 89018778, 4P1516, 52409643, 20340, 15-80567, 52495874, 15 80567 This is a compatible replacement part manufactured by AA Ignition. This blower motor resistor is NOT a genuine OEM part. Vehicle makes and their associated vehicle models are registered trademarks of their respective owners. These trademarks and part numbers are used in this listing only to identify the vehicles this blower motor resistor fits. AA Ignition is a registered trade mark of GWA Auto Parts Inc.