Maxine,

You mentioned, "I had already replaced the check valve but it didn't fix it. I have practically replaced everything on it except the motor and the switch. Someone said to take the switch apart and clean all the contacts and see if that works. I just haven't had time to do it. I really appreciate your reply to my problem".

This was posted in an email, not to this forum so I just wanted to make everyone aware

You're right, the copper contacts in the pressure switch could certainly be corroded or damaged, causing this problem. All of the suggestions above from Nightrider1987 and mrelmo is certainly good trouble-shooting info as well.
Hopefully you find the fix! Let us know if you do.

- MTR