No noise at all, even a low level hum, indicates no voltage at all to the pump. First try cycling the breaker and the other switches in the line several times. Could be crummy contacts. If that doesn't show anything then next step would be to use a voltmeter to check for voltage starting at the pump and working back to the breaker panel. If it's a 240 volt pump, which I assume it is, make sure you have 240 across the two lines, typically black and red, and 120V between each of those and neutral or ground. A common problem with pumps failing to start is the centrifugal starter switch contacts or an open starter capacitor in the pump but you would still hear a low level hum as the running winding is is always connected. This doesn't sound like your problem.
Always wear goggles when messing around these circuits. One slip with a probe and you may get molten metal flying around so protect your eyes.
Al