The coil on the switch reduces voltage to change the blower motor speed. One position of the switch should have almost no resistance and the other should have some. Of course on "off" there should be no continuity.
I agree you should be using a battery instead of a charger.


"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.