Nissan Repair: 2000 nissan frontier a/c, nissan frontier, electrical problem

Question
my a/c wont work it throws out humid air and on occassion will throw out cool air but only for a short amount of time ive taken it to a local garage and they cant find the problem they said it was possibly an electrical problem please help me

Answer
Vickie,

I need to know if the compressor is coming on when the air is on.  Also, when it puts out cool air I am sure the compressor is on.  This all leads to system not beign charged all the way or the pressure switch going out or a problem with the airconditioning switch.  Email me back with more info and I will give you more specific information.