A/C Performance
Use this test and the accompanying chart in order to aide in the evaluation of the air conditioning (A/C) system performance. While increased engine RPM may provide extra capacity and cooler A/C discharge temperatures, the test results may not be repeatable due to other variables. The following test procedure must be followed.
Tools Required
J 21213-A Four Jack Dual Range Temperature Tester
- Engage the parking brake.
- Park the vehicle indoors or in a shaded area.
- Open the hood, the doors, and the windows in order to ventilate the interior.
- Vent the engine exhaust, if necessary.
- Install the high and the low side pressure gauges.
- Record the ambient temperature at the vehicle.
- Record the temperature and the relative humidity by using a psychrometer or by consulting the local weather bureau.
- Close the doors.
- Close all of the windows.
- Set the mode control to the upper mode setting.
- Depress the A/C and the Max/Recirculation buttons.
- Set the blower speed to the HIGH position.
- Set the temperature control to the FULL COLD position.
- Open the A/C outlets.
- Install the J 21213-A or the equivailant into the left center A/C outlet.
- Place the transmission in park (auto) or in neutral (manual).
- Start the engine.
- Stabilize the engine speed to idle RPM.
- Start the timer.
- Operate the A/C system for about 5 minutes or until the left center outlet reaches the lowest temperature.
- Record the following data:
- Turn the ignition off.
- Compare the readings with the following table.
- Normally operating A/C systems should be within --15°C (5°F) and 68.9-137.9 kPa (10-20 PSI) of the levels appearing in the table
| • | The left outlet air temperature |
| • | The high-side pressure |
| • | The low-side pressure |
Relative Humidity | Ambient Air Temperature | Maximum Low Side Pressure | Engine Speed | Maximum Left Center Air Outlet Temperature | Maximum High Side Pressure |
|---|---|---|---|---|---|
20% | 21°C (70°F) | 223 kPa (32 psi) | Idle | 7°C (45°F) | 1 138 kPa (165 psi) |
20% | 27°C (80°F) | 239 kPa (35 psi) | Idle | 8°C (47°F) | 1 255 kPa (182 psi) |
20% | 32°C (90°F) | 277 kPa (35 psi) | Idle | 12°C (53°F) | 1 469 kPa (213 psi) |
20% | 38°C (100°F) | 330 kPa (48 psi) | Idle | 16°C (60°F) | 1 737 kPa (252 psi) |
20% | 43°C (110°F) | 385 kPa (56 psi) | Idle | 19°C (67°F) | 2 020 kPa (293 psi) |
30% | 21°C (70°F) | 230 kPa (33 psi) | Idle | 10°C (49°F) | 1 269 kPa (184 psi) |
30% | 27°C (80°F) | 268 kPa (39 psi) | Idle | 11°C (52°F) | 1 400 kPa (203 psi) |
30% | 32°C (90°F) | 323 kPa (47 psi) | Idle | 15°C (59°F) | 1 648 kPa (239 psi) |
30% | 38°C (100°F) | 376 kPa (55 psi) | Idle | 19°C (66°F) | 1 862 kPa (270 psi) |
30% | 43°C (110°F) | 430 kPa (62 psi) | Idle | 22°C (72°F) | 2 103 kPa (305 psi) |
40% | 21°C (70°F) | 250 kPa (36 psi) | Idle | 10°C (49°F) | 1 269 kPa (184 psi) |
40% | 27°C (80°F) | 293 kPa (43 psi) | Idle | 12°C (54°F) | 1 462 kPa (212 psi) |
40% | 32°C (90°F) | 341 kPa (50 psi) | Idle | 17°C (62°F) | 1 682 kPa (244 psi) |
40% | 38°C (100°F) | 391 kPa (57 psi) | Idle | 20°C (68°F) | 1 931 kPa (280 psi) |
50% | 21°C (70°F) | 248 kPa (36 psi) | Idle | 10°C (50°F) | 1 241 kPa (180 psi) |
50% | 27°C (80°F) | 296 kPa (43 psi) | Idle | 13°C (56°F) | 1 448 kPa (210 psi) |
50% | 32°C (90°F) | 355 kPa (52 psi) | Idle | 18°C (65°F) | 1 675 kPa (243 psi) |
50% | 38°C (100°F) | 417 kPa (61 psi) | Idle | 21°C (70°F) | 1 999 kPa (290 psi) |
60% | 21°C (70°F) | 251 kPa (36 psi) | Idle | 11°C (51°F) | 1 227 kPa (178 psi) |
60% | 27°C (80°F) | 300 kPa (44 psi) | Idle | 14°C (57°F) | 1 420 kPa (206 psi) |
60% | 32°C (90°F) | 365 kPa (53 psi) | Idle | 19°C (66°F) | 1 689 kPa (245 psi) |
60% | 38°C (100°F) | 427 kPa (62 psi) | Idle | 22°C (71°F) | 1 999 kPa (290 psi) |
70% | 21°C (70°F) | 256 kPa (37 psi) | Idle | 10°C (50°F) | 1 234 kPa (179 psi) |
70% | 27°C (80°F) | 299 kPa (43 psi) | Idle | 14°C (57°F) | 1 420 kPa (206 psi) |
70% | 32°C (90°F) | 379 kPa (55 psi) | Idle | 19°C (66°F) | 1 737 kPa (252 psi) |
80% | 21°C (70°F) | 254 kPa (37 psi) | Idle | 10°C (50°F) | 1 200 kPa (174 psi) |
80% | 27°C (80°F) | 305 kPa (44 psi) | Idle | 14°C (57°F) | 1 407 kPa (204 psi) |
80% | 32°C (90°F) | 387 kPa (56 psi) | Idle | 19°C (67°F) | 1 717 kPa (249 psi) |
This is not a maximum A/C Capacity Test. Increased engine temperatures may not provide repeatable test results. | |||||
