The pin is in the upper surface of the fan housing, the side that faces the cover.
When the cover is lowered, it depresses the switch pin and cuts power to the fan to prevent it from running with the cover closed.
But your issue is with the lift motor, not with the fan itself, right?
I am not sure if that cutout switch has any connection to the circuit of the lift assembly. I just mentioned it as it is the one thing that gives problems pretty frequently.
Like I said before, your description sounds more like the lift motor is getting overloaded. But I have never had that type of Fantastic Fan myself, only the manual lift version.
