Nissan Repair: AC 2000 Exterra, push button switch, expansion valve

Question
The A/C is intermittently working. It will work good for different periods of time and then it the compressor is not cycling on. Had the comp replaced lines replaced the cycling switch on the drier replaced the push button switch on the dash that illuminates replaced and the mechanic said he replaced something he called a circuit that looked two coils or something. Another person has the same vehicle and he told me to replace the temp control sensor by the evaporator. I purchased the sensor removed the glove box and could see the sensor, however looks like the casing has to be split apart so i stopped. It looks like it could be a job to do. Is it simple or should i let a mechanic do it and also does it sound like that is the fix for this thing?

Answer
Lee,

Yes, the expansion valve needs to be replaced.  It is a difficult job and it does require the case to be split and removed.  Also, the refrigerant has to be recovered to get the evaporator out and then reassembled, evacuated and recharged to complete the job.