ClassicCar

Hi Lance, it depends on which control you have one is 42,late 46 and 47. The other is early 46. The 42, L46, 47 control just makes contact, part way down it mutes the radio and all the way down it activates a solenoid in the radio that turns a ratchet mechanism one sixth of a turn for every push. The plug on this one has 3 prongs/contacts. The early 46 unit does all of the above but in addition has a volume control built in. To operate the foot vol. cont. you turn the volume control on the radio all the way counter-clockwise and it switches to the foot control! The plug on this unit has 6 smaller prongs/ contacts and is not interchangeable with the other one. BTW these same footswitches were used by Nash for the same years plus Nash used the 47 control thru 1950.

Does anyone know where I can get a replacement knob for the foot control?

If your are trying to see if it works before putting it in the car, remember that the foot switch needs to be grounded as well (to the radio itself is sufficient) in order to work properly.