REFRIGERANT SYSTEM TESTS

1. Adjust the climate controls for maximum cooling.

(1) Start the engine.

(2) Select MAX COLD operation.

(3) Set the blower motor speed to maximum.

2. Stabilize the in-vehicle temperature at 21-27 ×C {70-80 ×F}.

3. Maintain the engine speed at 1,500 rpm.

Note

• When the ambient temperatures exceed 38 ×C {100 ×F}, do not run the engine above normal idle speed.

4. Determine the compressor discharge (high) pressure.

(1) Record the ambient temperature.

(2) Record the discharge (high) pressure.

(3) The system performance is acceptable when the pressure reading falls between the upper and lower limits shown.

Note

• In ambient temperatures between 38-43 ×C {100-110 ×F}, the system performance pressures will be the same as those for ambient temperatures shown on the chart in the 32-38 ×C {90-100 ×F} range.

5. Determine the compressor suction (low) pressure.

(1) Record the ambient temperature.

(2) Record the suction (low) pressure.

(3) The system performance is acceptable when the pressure reading falls between the upper and lower limits shown.

Note

• In ambient temperatures between 38-43 ×C {100-110 ×F}, the system performance pressures will be the same as those for ambient temperatures shown on the chart in the 32-38 ×C {90-100 ×F} range.

6. Determine the magnetic clutch ON time.

(1) Record the ambient temperature.

(2) Record the magnetic clutch ON time in seconds.

(3) The system performance is acceptable when the recorded time falls between the upper and lower limits shown.

Note

• When the ambient temperature is above 26 ×C {80 ×F}, the magnetic clutch may not cycle.

7. Determine the magnetic clutch OFF time.

(1) Record the ambient temperature.

(2) Record the magnetic clutch OFF time in seconds.

(3) The system performance is acceptable when the recorded time falls between the upper and lower limits shown.

Note

• When the ambient temperature is above 26 ×C {80 ×F}, the magnetic clutch may not cycle.

8. Determine the total magnetic clutch cycle time.

(1) Record the ambient temperature.

(2) Record the time the magnetic clutch is engaged plus the time it is disengaged (time ON plus time OFF).

(3) The system performance is acceptable when the recorded time falls between the upper and lower limits shown.

Note

• When the ambient temperature is above 26 ×C {80 ×F}, the magnetic clutch may not cycle.

9. Determine the magnetic clutch cycle rate per minute.

(1) Record the ambient temperature.

(2) Record the number of magnetic clutch cycles occurring in one minute.

(3) The system performance is acceptable when the recorded number of cycles falls between the upper and lower limits shown.

Note

• When the ambient temperature is above 26 ×C {80 ×F}, the magnetic clutch may not cycle.

10. Determine the center A/C register discharge temperature.

(1) Record the ambient temperature.

(2) Record the center A/C register discharge temperature.

(3) The system performance is acceptable when the center A/C register discharge temperature falls between the upper and lower limits shown.

Note

• In ambient temperatures between 38-43 ×C {100-110 ×F}, the A/C register discharge temperatures will be the same as those for ambient temperatures shown on the chart in the 32-38 ×C {90-100 ×F} range.