The Headlight Switch controls various functions like the headlights, door panel lights, dome lamps including dimming the lights on your dash. If you cannot do these functions on your lights then this maybe the problem. Please make sure that the part being replaced is identical. Fits the following vehicles: 2002 Avalanche 1500 2002 Avalanche 2500 1999-2002 Silverado 1500 2001-2002 Silverado 1500 HD 1999-2002 Silverado 2500 2001-2002 Silverado 2500 HD 2001-2002 Silverado 3500 2000-2002 Suburban 1500 2000-200 Suburban 2500 2000-2002 Tahoe 1999-2002 Sierra 1500 2001-2002 Sierra 1500 HD 1999-2002 Sierra 2500 2001-2002 Sierra 2500 HD 2001-2002 Sierra 3500 2000-2002 Yukon 2000-2002 Yukon XL 1500 2000-2002 Yukon XL 2500 Replaces part numbers: 15755595, 15738843, D1534G, SW2157, D1534G, Wells SW2157 This is a compatible replacement part manufactured by AA Ignition. This headlight switch is NOT a genuine OEM part. 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 headlight switch fits. AA Ignition is a registered trade mark of GWA Auto Parts Inc.