Component Tests

R-134a Manifold Gauge Set:

SPECIAL TOOLS

1. Connect the R-134a Manifold Gauge Set. Manifold Gauge Set Connection
2. Adjust the climate controls for maximum cooling.
- Start the engine.
- Select MAX A/C operation.
- Set the blower motor speed to maximum.







3. Stabilize the in-vehicle temperature at 21°C-27°C (70°F-80°F).







4. Maintain the engine speed at 1500 rpm.

NOTE: When the ambient temperatures exceed 38°C (100°F) do not run the engine above normal idle speed.







5. 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.

NOTE: In ambient temperatures between 38°C-43°C (100°F-110°F), the system performance pressures will be the same as those for ambient temperatures in the 32°C-38°C (90°F-100°F) range.







6. 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.

NOTE: In ambient temperatures between 38°C-43°C (100°F-110°F), the system performance pressures will be the same as those for ambient temperatures in the 32°C-38°C (90°F-100°F) range.







7. Determine the A/C clutch ON time.
1. Record the ambient temperature.
2. Record the A/C clutch ON time in seconds.
3. The system performance is acceptable when the recorded time falls between the upper and lower limits.

NOTE: When the ambient temperature is above 26°C (80°F), the A/C clutch may not cycle.







8. Determine the A/C clutch OFF time.
1. Record the ambient temperature.
2. Record the A/C clutch OFF time in seconds.
3. The system performance is acceptable when the recorded time falls between the upper and lower limits.

NOTE: When the ambient temperature is above 26°C (80°F), the A/C clutch may not cycle.







9. Determine the total A/C clutch cycle time.
1. Record the ambient temperature.
2. Record the time the A/C 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.

NOTE: When the ambient temperature is above 26°C (80°F) the A/C clutch may not cycle.







10. Determine the A/C clutch cycle rate per minute.
1. Record the ambient temperature.
2. Record the number of A/C clutch cycles occurring in one minute.
3. The system performance is acceptable when the recorded number of cycles fall between the upper and lower limits.

NOTE: When the ambient temperature is above 26°C (80°F), the A/C clutch may not cycle.







11. 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.

NOTE: In ambient temperatures between 38°C-43°C (100°F-110°F), the A/C register discharge temperatures will be the same as those for ambient temperatures shown on the chart in the 32°C-38°C (90°F-100°F) range.