Hello Mustang World!!!

A/C comp. won't turn on. This is my first post. I have been reading for a long time but finally decided to join. I am so excited about the possibilities of this venture. I purchased a 2000 v6 Mustang that was seriously in distress. I have never owned a car that has had so much wrong with it. I have listed everything wrong on three legal pad pages, WHEW! With all of that said, I have replaced the module inside the inner right fender. I have replaced the A/C control switch. I have checked the fuse block under the hood and under the dash and all the fuses are good. I am not getting any power to the high pressure switch. When I turn the defroster and the MAX A/C on, the cooling fan does not stay continuously on. The A/C is charged and has worked for me since I purchased the car. It is HOT here in the south..... Any ideas?