System Description
WARNING: This page is about a different car, the 1998 Chevrolet Monte Carlo and 1998 Chevrolet Lumina. However, it is still accessible from the selected car via links, so may be relevant.
The manual A/C-heater system delivers heated or cooled and dehumidified air. System is a Variable Displacement Orifice Tube (VDOT) design, using a constant run Harrison V5 compressor. Air distribution is controlled through a manual A/C-heater control panel and electric/vacuum-operated doors.
Refrigerant flow is metered through a fixed expansion (orifice) tube, located in high-pressure liquid line between condenser outlet and evaporator inlet. If high-side pressure reaches about 455-525 psi (32-37 kg/cm2 ), a pressure relief valve on compressor opens, venting refrigerant to atmosphere. This prevents damage to system from excessive pressure.