My square d switch will not close

Your description is pretty vague. Square D "switch" breaker? Switch box? Pump switch? Wall switch? "Won't close"-won't turn on?

Hey Walt, You piggybacked on a 7 year old dead thread so I gave you one of your own. More details please. Is the breaker opened up? Do you have power to the control box? Check and let me know.
What type of pump and what horsepower is it? Back to you Tom

If the points won't close, and if we are talking about the switch on a water well, then either the switch is defective or you need to reset the switch with the reset lever on the side. I am assuming you mean the points closing so as to turn the pump on.