I get a voltage of 240 in to the switch and across the swithc when no load is on it, but lose everything when I hook up the pump. Does this indicate the pump is bad or my wireing is poor?

Time answer some basic questions and to run some basic tests. Do you have a voltmeter?

What is the amperage required by the pump? How far is the pump from the breaker. What gauge wire are you using? How many conductors are in the run to the pump? What colors are you using?

The first place I would start is the breaker. I would verify that I am getting 240 VAC between the hot (ungrounded) conductors. (These would be the two conductors that are screwed into each breaker.)

Next, I would move upstream to the next Junction Box and measure between the two current carrying conductors, if you do not see 240 VAC, turn the breaker off and open the connections to see if there is a bad connection.

Continue, down the line until you have checked every connection point.

When you turn pump on and lose voltage, does breaker trip?
Since voltage is lost when load is applied, an Electrician might check voltage from breaker, in to 240 switch and when turned on 240 volts out of switch. Then 240 volts to pump.