A/C System Performance

Ensure ambient temperature is 77-86°F (25-30°C). Connect manifold gauge set. Run engine at idle. Turn A/C switch on. Operate blower in high speed. Set temperature selector for maximum cool setting. Set air source lever to recirculated air position. Close all doors. Check low-side and high-side pressure readings. Low-side pressure reading should be 21-43 psi (1.5-3.0 kg/cm² ), and high-side pressure readings should be 199-270 psi (14.0-19.0 kg/cm² ). Outlet air at center vent should be considerably colder, about 20°F (-6.7°C) colder, than outside ambient air temperature.