Nissan Repair: Nissan Sentra Air Conditioner, nissan sentra, r 134

Question
Should I hear the air compressor engage when I press the AC button? No cold air emitting at all or change in engine, or should I check/add freon before I spend the money on a new compressor. Car Make (2001 Nissan Sentra)

Answer
C5,

Yes, the system probablyneeds to be evacuated and recharged with R-134.  This is the new stuff since they stopped using R-12 back in 1992/1993.  So, the new refrigerant eventually gasses out and you have to charge it.  Now, since you say there is no cooling, compressor noise or anything I say it is out and that is why the compressor will not cycle.  Have it evacuated and charged and you might get lucky and not have a leak or anything wrong.  But, to know you have to get it done.