That 'switch' is wired NC, Normally Closed and when that wheel articulates back too far, you will hear a click and it will lift a conductive plate within that switch breaking the ground connection between the two wires. Once this happens, the machine stops functioning correctly. If you were to just wire those two wires going into that switch together, it would function, that's how you know if you got a bad switch, but it's a limit switch that really needs to be properly setup to stop the lift from being lifted to high and coming off the slide-track or going over.