Manual Transaxle
ELECTRICAL SYSTEMThe air-conditioning and the heating and defrosting systems use the same controls for airflow, temperature, and A/C blower motor speed. These controls are located in the climate control assembly. Press the A/C switch and turn on the A/C blower motor to activate the air-conditioning system.
When the A/C switch is pressed, the [1][2]A/C relay closes. The A/C relay then supplies current to the A/C compressor clutch field coil which magnetically draws the A/C clutch toward and locks it to the A/C compressor clutch pulley. The engine then drives the A/C compressor. The A/C compressor pumps low-pressure gaseous refrigerant from the suction accumulator/drier, compresses it, and moves it into the A/C condenser core, where it cools and liquefies. The liquid refrigerant then passes through the A/C evaporator core orifice which restricts the refrigerant's flow and reduces its pressure before it enters the evaporator.
Since the refrigeration cycle is capable of providing more cooling than the air-conditioning system needs, it needs to be controlled. Operation of the A/C compressor pump, therefore, must be interrupted to ensure that the correct amount of refrigeration is supplied for proper air-conditioning system operation. As refrigerant is pumped from the low-pressure side, the pressure gradually decreases until it reaches 159 +/- 7 kPa (23 +/- 1 psi). At this point, the A/C cyclic switch and then the [1][2]A/C relay open, thereby de-energizing the A/C compressor clutch field coil and stopping the A/C compressor. High-pressure refrigerant gas on the discharge side of the A/C compressor will continue to pass through the A/C condenser core and the A/C evaporator core orifice.
(The refrigerant gas will not backflow through the closely fitted A/C compressor vanes.) When the A/C compressor is stopped, heat transfer from the circulating air to the evaporator refrigerant causes the refrigerant pressure in the low-pressure side to increase. When the pressure reaches approximately 317 kPa (46 psi), the A/C cyclic switch and then the [1][2]A/C relay close, energizing the A/C compressor clutch field coil and starting the A/C compressor again. This completes the clutch/pressure operation cycle.
Also, when head pressure rises to approximately 3068 kPa (445 psi), the single function refrigerant containment switch opens. The [1][2]A/C relay then opens, thereby de-energizing the A/C compressor clutch field coil and stopping the A/C compressor. When head pressure reaches approximately 1724 kPa (325 psi), the single function refrigerant containment switch closes. The A/C relay then closes, energizing the A/C compressor clutch field coil and energizing the A/C compressor again.
Note: The electric cooling fan is controlled by a separate fan control relay. Hence, the dual function refrigerant containment switch contains only a single set of contacts and will be referred to as the single function refrigerant containment switch for these vehicle applications.