System Performance Check

Fig. 3 Gauge manifold installation.:

1. Connect suitable gauge manifold following manufacturer's instructions, Fig. 3.

Fig. 4 Proper positioning of thermometers for performance test:

2. Insert dry bulb thermometer in cold air outlet and position wet/dry bulb thermometer (psychrometer) as close as possible to blower inlet, Fig. 4.

Fig. 7 A/C system performance specifications.:

3. Start engine, open hood, front doors and windows, place temperature control at MAX COLD, mode control in VENT position and air selector in recirculation, and operate blower at maximum speed.
4. Operate engine at 1500 RPM and check system pressures, inlet and discharge temperatures, and relative humidity after 10 minutes of operation.
5. Ideal system pressures and discharge temperature for ambient conditions are shown in Fig. 7.
6. System is operating properly if pressures and discharge temperature are within 10% of ideal value for given ambient temperature and relative humidity. If system pressures are not within specifications, refer to ``SYSTEM PRESSURE DIAGNOSIS.''