What's This Knob?

[CS72Roadster]

I just bought a 72 convertible. I have previously owned a 69 and an 81. Neither of them had this round knob between the vacuum bypasses for the headliights and wiper door. I can't figure out what it is supposed to do. I know it must be a stupid question, but I would appreciate your help here.

Thanks...

 

[Stingray6974]

Hi CS72,
That knob turns off the wiper motor while the door is open. For instance if you want to change the blades. Turning the ignition off will not stop the wiper motor.
Mike

 

[CS72Roadster]

Great! Thanks for the reply.

 

[tangee-vette]

On my 77' it's the trip meter re-set knob. Push up and turn to zero out the trip meter.