I am thinking that the push button switch is a momentary switch, ( one that makes connection as long as the button is depressed). With looking at the wiring schematics for a 400 series, and checking part numbers that are identical for a 430 and a 445 this appears how it is. After looking up a switch for a 445 series 3 the part number is different, and could be a latching switch. Really all you have to do is figure out how complete the connection without holding the button down.
