Nissan Repair: 2000 Maxima Air Conditioning, refrigerant r134, pressure switch

Question
AC always blows very cold.  Yesterday a little too cold.  I slid the temp over about 3/4 an inch.  Worked fine.  This morning warm air.  Fuses all ok.  I don't think the compressor is kicking in.  Any ideas?

Answer
Alan,

You will need to perform a systems check on the pressures.  If you have a set of gauges to check what is going on.  My bet is the pressure cycling switch is defective and there is not a blockage or the system is low on refrigerant (R134).  The pressure switch is under $50 bucks.  Try to rund the system on Max, recycle and see what happens as the control for temperature could be defective.  These are usually bulletproof so I think it would be the pressure switch as my first thought.