## Air Conditioning

#### System Description

21-10

The air conditioning system removes heat from the passenger compartment by circulating refrigerant through the system as shown below.

1. A/C PRESSURE SWITCH

   (Triple function)

   When the refrigerant is below 196kPa (2.0 kgf/cm2, 28 psi) or above 3,140 kPa (32 kgf/cm2, 455 psi), the A/C pressure switch opens the circuit to the A/C switch and stops the air conditioning to protect the compressor.

   When the refrigerant is above 1,520 kPa (15.5 kgf/cm2, 220 psi), the A/C pressure switch switches the radiator and condenser fans to high speed.

2. EXPANSION VALVE

   (Meters the required amount of refrigerant into the evaporator)

3. BLOWER FAN
4. EVAPORATOR

   (Absorption of heat)

5. EVAPORATOR TEMPERATURE SENSOR
6. RELIEF VALVE

   (Relieves pressure at the compressor when the pressure is too high)

7. COMPRESSOR

   (Suction and compression)

8. HIGH PRESSURE VAPOUR
9. HIGH PRESSURE LIQUID
10. LOW PRESSURE LIQUID
11. LOW PRESSURE VAPOUR
12. CONDENSER

    (Radiation of heat)

13. RECEIVER/DRYER

    (Traps debris, and removes moisture)

This vehicle uses HFC-134a (R-134a) refrigerant which does not contain chlorofluorocarbons. Pay attention to the following service items:

- Do not mix refrigerants CFC-12 (R-12) and HFC-134a (R-134a). They are not compatible.
- Use only the recommended polyalkyleneglycol (PAG) refrigerant oil (DELPHI DH-PS) designed for the R-134a compressor. Intermixing the recommended (PAG) refrigerant oil with any other refrigerant oil will result in compressor failure.
- All A/C system parts (compressor, discharge line, suction line, evaporator, condenser, receiver/dryer, expansion valve, O-rings for joints) have to be proper for refrigerant R-134a. Do not confuse with R-12 parts.
- Use a halogen gas leak detector designed for refrigerant R-134a.
- Use a vacuum pump adapter which is equipped with a check valve to prevent the backflow of the vacuum pump oil.
- Separate the manifold gauge sets (pressure gauges, hoses, joints) for refrigerants R-12 and R-134a. Do not confuse them.

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