Odd Original Light Switch Malfunction

[ericr]

has anyone had this issue: the lighting switch has the correct détentes at the steering wheel, yet, every position (except the off position) turns on only both the high/low beams in each headlight. I unplugged one of the headlamp conduits and tested each one of the three contacts with a test light and each is indeed always hot, no matter where the switch is at the steering wheel. The only position working correctly is the off position.

late '29 roadster with two-lamp headlights, and 2-tooth column