A/C Compressor Torque Test Procedure (Outside Air Temperature Higher Than 42~F)
TOOLS NECESSARY FOR TORQUE TEST PROCEDURE:Clicker-type torque wrench (3/8 drive) set at 9.5 ft.lbs.
10 mm socket, 12 mm socket, 13 mm socket standard and deep (all should be 12 pt.)
Standard or flex-head ratchet
Phillip's head screw driver
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 the 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 REPLACED-- SEE 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 on to next step.
3. 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--REFER TO COMPRESSOR REPLACEMENT PROCEDURE.
^ If compressor is operating normally the vehicle is OK and can be retailed.
SPECIFIC VEHICLE PROCEDURES
300ZX
Install 10 amp fuse in the lower right corner of the fuse block, as shown in the illustration below. The compressor is easily accessible at the top left of the engine. Check according to general procedure above. Remove 10 amp fuse.
200 SX (VG30):
The compressor is easily accessible at the top left of the engine. Check according to general procedure.
200SX (4 cyl.):
The compressor must be accessed from underneath the vehicle. Place vehicle on hoist and raise all the way up. Remove dust shield which is located directly below the engine by removing the six sheet metal screws. On this vehicle, it is necessary to use the 13 mm deep socket to provide clearance from stabilizer bar. Check vehicle according to general procedure and reinstall dust shield.
EXTENDED STORAGE SWITCH:
MAXIMA:
Turn on extended storage switch as shown below. The compressor unit is located at the right of the engine compartment and can be accessed from the top. Using a torque wrench and 13 mm short socket, check compressor turning torque and then check for noise according to the general procedure given above. Turn off extended storage switch.
NOTE: Be careful not to dislocate coil wire during checking procedure.
VAN:
Raise engine cover to access the compressor unit which is mounted at the left side of the engine. Space is limited due to the location of the fan shroud, but the turning torque can be checked using a torque wrench and 13 mm short socket.
NOTE: The use of a stubby ratchet may be helpful when doing the 3 full turns.
STANZA WAGON 2WD/4WD:
The A/C compressor can only be accessed from underneath the vehicle. Place vehicle on hoist and raise all the way up. Locate the right dust shield and remove tne four plastic screws and one 10 mm bolt. Then pull the shield back to gain access to the compressor. Check the compressor according to the general procedure and reinstall the dust cover.