Nissan Repair: 1999 Nissan Sentra A/C Compressor Problems, nissan sentra, c button

Question
Dear Expert,

I recently bought a 1999 Nissan Sentra.  I tried to see if the A/C works and the light on A/C button turns on but only blows hot air.  The clutch on the compressor is not engaging.  I checked the A/C fuse at the dash and the A/C fusible link inside the hood and both are ok.  Do you have any suggestions as to why the compressor wont start?

Also the small pump for the wipers does not work when I try to wipe my windows.  I checked the pump separately with direct current from the battery and it does work.  Do you have any suggestion as to why the pump is not getting any current?

Many thanks,


Jose Sanchez

Answer
Jose,

The unit is probably low on refrigerant and that is keeping the clutch from applying.  Second, if the compressor relay is defective or the pressure switch is defective it can cause the pump not to activate.

The wiper pump circuit could be defective.  Check for current at the connection.  It is most probably the switch since you say it works when power is applied.  Also, check the fuses to make sure you are getting power to the switch.