Electric Assist Choke: Operation
Bi-metal spring reacts to heat from two sources. First source of heat is from special heat conductive mounting bolts (304", 345" and 392" V8) or lower choke housing (400" V8) which extends into exhaust passage of intake manifold. Second heat source is electric heating element (calrod) mounted inside choke spring housing. Flow of electric current to heating element is controlled by a thermostatic switch mounted on intake manifold next to choke. Switch allows electric current to flow to heating element at switch temperatures between approximately 58°F-130°F. Electric circuit is from ignition switch, through thermostatic switch and heating element to ground through choke spring housing.