AIR CONDITIONING 1B-7 Electronic Thermostat The thermostat consists of the thermosensor (1) and thermostat unit (2) which functions electrically to reduce the noises being generated while the system is in oper- ation. The electronic thermosensor is mounted at the evapora- tor core outlet and senses the temperature of the cool air from the evaporator, Temperature signals are input to the thermostat unit. This information is compared by the thermo unit and the results in output to operate the A/C thermo relay and turn the magnetic clutch “ON” or “OFF” to prevent evaporator freeze-up.
A characteristic of the sensor is that the resistance de- creases as the temperature increases and the resis- tance increases as the temperature decreases. N1A0053E Legend 1. Reinforcement layer (Polyester) 2. External rubber layer 3. Internal rubber layer 4. Resin layer (Nylon) Service Charge Valves R-134a service charge valve shapes is different from the charge valves used in the R-12 system. The charging hoses have a quick-joint type fitting, to reduce refriger- ant loss during removal and installation. This type of valve also eliminates the possibility of cross charging R- 12 and R-134a systems when using approved service equipment.
N1A0052E Refrigerant Line Restrictions in the refrigerant line will be indicated by: 1. Suction line; A restricted suction line will cause low suction pressure at the compressor, low discharge pressure and little or not cooling. 2. Discharge line; A restriction in the discharge line generally will cause the discharge line to leak. 3. Liquid line; A liquid line restriction will be evidenced by low discharge and suction pressure and insuffi- cient cooling. Refrigerant flexible hoses that have a low permeability to refrigerant and moisture are used. These low permeability hoses have a special nylon layer on the inside. N1A0054E