The Dyson DC77 (UP14) Upright Switch Cam is in the lower duct assembly. This white cam engages the brushbar when the vacuum is out the locked position.

Replacement part number for the Dyson DC77 Upright Switch Cam is, 966518-01, DY-966518-01. DY-96651801.

Compatible with the following model:
Cinetic Big Ball
DC77/UP14 Animal Allergy USA (Iron/Bright Silver/Sprayed Nickel & Red) 206033-01
DC77/UP14 Animal Exclusive USA (Iron/Bright Silver/Sprayed Purple & Red) 206037-01
DC77/UP14 Animal Exclusive USA (Iron/Bright Silver/Sprayed Purple & Red) 208990-01
DC77/UP14 Animal Plus USA (Iron/Bright Silver/Satin Purple & Red) 206043-01
DC77/UP14 Animal Pro USA (Iron/Bright Silver/Satin Fuchsia & Blue) 206040-01
DC77/UP14 Animal USA (Iron/Bright Silver/Sprayed Purple & Red) 206031-01
DC77/UP14 Multi Floor Exclusive USA (Iron/Bright Silver/Sprayed Dark Red & Red) 206036-01
DC77/UP14 Multi Floor Exclusive USA (Iron/Bright Silver/Sprayed Silver & Red) 206035-01
DC77/UP14 Multi Floor Exclusive USA (Iron/Bright Silver/Sprayed Dark Blue & Red) 206038-01
DC77/UP14 Multi Floor Exclusive USA (Iron/Bright Silver/Satin Yellow & Red) 206034-01
DC77/UP14 Total Clean USA (Iron/Bright Silver/Satin Yellow & Red) 206042-01
DC77/UP14 US (Iron/Bright Silver/Sprayed Silver & Red) 210668-01