HVAC Pressure Switch. 2001 Chevrolet Silverado 3500 6.0L V8; High Pressure Cutout | For Pigtail Use 1711880;. 2001 Chevrolet Silverado 3500 6.6L V8; High Pressure Cutout | For Pigtail Use 1711880;. 2001 Chevrolet Silverado 3500 8.1L V8; High Pressure Cutout | For Pigtail Use 1711880;.