General Procedure:

1. With the vehicle ignition switch "OFF", use torque wrench and 13 mm socket to check the turning torque of the A/C compressor. Pull on the torque wrench with only enough pressure to move the compressor shaft--rotate shaft at least one half turn to reach the point of maximum compressor resistance. CAUTION: IF THE SHAFT SEEMS TO HAVE HIGH RESISTANCE, OR IS SEIZED, DO NOT OVER STRESS THE SHAFT NUT AS IT WILL CAUSE FURTHER DAMAGE.

MAKE SURE WRENCH IS SET AT 9.5 FT/LBS.
CONDITION 1:
If torque wrench clicks while pulling one half turn:
This is the end of procedure. COMPRESSOR MUST BE REPLACEDSEE THE COMPRESSOR REPLACEMENT PROCEDURE.

CONDITION 2:
If torque wrench does not click while pulling one half turn:
Go on to next step.
2. Using ratchet and 13 mm socket, turn the compressor shaft three full turns. If torque appears to increase while turning, check torque again with torque wrench). (If greater than 9.5 ft.lbs.--COMPRESSOR MUST BE REPLACED) If compressor feels OK during the three turns, go an to next step.

NOTE: DO NOT PERFORM NEXT STEP IF OUTSIDE AIR TEMPERATURE IS LOWER THAN 23~F. The procedure can be continued if the vehicle is moved into a building which has a temperature above 23~F.
3a. ALL VEHICLES:
Before the A/C unit will switch on, the dual pressure or low pressure switch must be jumped (shorted) and the inside temperature of the vehicle must be at least 41~F. Refer to "SPECIFIC VEHICLE PROCEDURES" for instructions on jumping the appropriate switches. MAKE SURE IGNITION AND A/C ARE "OFF" BEFORE JUMPING ANY SWITCHES.

If it is colder than 41~F inside the vehicle, start the engine and let it run for 10 minutes with the heater set as follows:

^ Set heater at full hot position.

^ Set air intake to "recirculate".

^ Place fan at maximum speed.

Be sure A/C is switched "off" and all doors are closed.


3b. MAXIMA (MANUAL/AUTO A/C) & 300ZX AUTO A/C:
On these models, the A/C compressor will not operate at cold temperatures unless the ambient temperature switch or sensor is jumped (shorted). See "SPECIFIC VEHICLE PROCEDURES" for the proper method of jumping the necessary switch or sensor for each applicable model. Once the switch/ sensor has been shorted, proceed to step #4.


4. Run engine with A/C "ON" for five minutes. Carefully listen to compressor for noticeable noise while engine is running.

^ If you can hear a screeching belt or grinding noises coming from compressor unit, COMPRESSOR MUST BE REPLACED--SEE THE COMPRESSOR REPLACEMENT PROCEDURE.

^ If compressor is operating normally the vehicle is OK and can be retailed.


5. Re-connect ambient temperature sensors/switches and low /dual pressure switches. Reinstall any parts removed during testing procedure.