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A/C System Performance

  1. Park vehicle out of direct sunlight. Connect manifold gauge set to service valves. Start and run engine at 1500 RPM. Set A/C controls to MAX A/C and maximum blower motor speed.
  2. Close doors and windows. Insert thermometer in center vent. Operate system for 10 minutes to allow system to stabilize. Measure center vent output temperature.
  3. At about 68°F (20°C) ambient temperature, high side pressures should be approximately 100-200 psi (7.0-14.1 kg/cm2 ). Low side pressures should be approximately 24-46 psi (1.7-3.2 kg/cm2 ).
  4. As low side pressure decreases, high side pressure should increase. When A/C clutch disengages, low side pressure will increase and high side pressure should decrease. See A/C SYSTEM HIGH SIDE PRESSURE SPECIFICATIONS  table.
    A/C SYSTEM HIGH SIDE PRESSURE SPECIFICATIONS

    Ambient Temp. °F (°C) Pressure psi (kg/cm2 )
    60 (16) 75-175 (5.3-12.3)
    70 (21) 100-200 (7.0-14.1)
    80 (27) 128-230 (8.9-16.1)
    90 (32) 150-260 (10.5-18.3)
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