SAFETY PRECAUTIONS
| WARNING | Wear safety goggles and gloves when servicing the refrigeration system to prevent severe damage to eyes and hands. |
Because R-134a refrigerant is a hydro fluorocarbon (HFC) which contains hydrogen atoms in place of chlorine atoms, it will not cause damage to the ozone layer.
Ozone filters out harmful radiation from the sun. To assist in protecting the ozone layer, Mitsubishi Motors Corporation recommends an R-134a refrigerant recycling device.
Refrigerant R-134a is transparent and colorless in both the liquid and vapor state. Since it has a boiling point of -29.8°C (-21.64°F) at atmospheric pressure, it will be a vapor at all normal temperatures and pressures. The vapor is heavier than air, non-flammable, and non-explosive. The following precautions must be observed when handling R-134a.
| WARNING | Do not heat R-134a above 40°C (104.0°F) or it may catch fire and explode. |
R-134a evaporates so rapidly at normal atmospheric pressures and temperatures that it tends to freeze anything it contacts. For this reason, extreme care must be taken to prevent any liquid refrigerant from contacting the skin and especially the eyes. Always wear safety goggles when servicing the refrigeration part of the A/C system. Keep a bottle of sterile mineral oil handy when working on the refrigeration system.
- If any liquid refrigerant gets into your eyes, use a few drops of mineral oil to wash them out. R-134a is rapidly absorbed by the oil.
- Next, splash your eyes with plenty of cold water.
- Call your doctor immediately even if irritation has ceased.
| CAUTION | Keep R-134a containers upright when charging the system. |
In most instances, moderate heat is required to bring the pressure of the refrigerant in its container above the pressure of the system when charging or adding refrigerant.
A bucket or large pan of hot water not over 40°C (104.0°F) is all the heat required for this purpose. Do not heat the refrigerant container with a blow torch or any other means that would raise temperature and pressure above this temperature. Do not weld or steam-clean on or near the system components or refrigerant lines.
| WARNING | A leak detector for R-134a should be used to check for refrigerant gas leaks. |
| CAUTION | Do not allow liquid refrigerant to touch bright metal or it will be stained. |
When metering R-134a into the refrigeration system, keep the supply tank or cans in an upright position. If the refrigerant container is on its side or upside down, liquid refrigerant will enter the system and damage the compressor.
Refrigerant will tarnish bright metal and chrome surfaces, and in combination with moisture can severely corrode all metal surfaces.
CONDENSER FAN AND RADIATOR FAN CONTROL
The PCM judges the required revolution speed of radiator fan motor and condenser fan motor using the input signals transmitted from A/C switch, output shaft speed sensor and engine coolant temperature sensor. The PCM activates the fan control relays to drive the radiator fan motor and condenser fan motor.
When operating the air conditioning switch
- The air thermo sensor, which senses the temperature of the air flowing out of the evaporator, deactivates the compressor at 3°C (37.4°F) or below.
- The dual pressure switch turns OFF when the refrigerant pressure becomes excessively high or low, thus protecting the compressor circuit (Scheme 31)
- When the air thermo sensor is activated, and the ignition switch, blower switch, and air conditioning switch are ON, the A/C compressor clutch relay is energized.
When operating the mode selection dial
- The air conditioning will work when the mode selection dial is set to the "Defroster" or "Defroster/foot" position, or the temperature control dial is set to the "MAX A/C" position. In other dial positions, when the air conditioning switch is turned on, the air conditioning will work.
Scheme 31
INTERIOR TEMPERATURE SENSOR CHECK
When the resistance between the sensor terminals is measured under two or more temperature conditions, the resistance should approximately satisfy the illustrated values.
Scheme 32
The temperature conditions when checking should not exceed the range shown in the diagram.
Scheme 33
PHOTO SENSOR CHECK
- Connect scan tool MB991958, and check the data list of the photo sensor. (Refer to «HOW TO CONNECT THE SCAN TOOL (MUT-III)»(ref-205493-S06900388422005111900000) )
- Check that the displayed value changes when you cover the photo sensor with your hands.