COUPLING AS 3201989 - Caterpillar

System Condition 12
Water is in the vents.
Water is leaking from the unit.Probable Cause
The non-return valve of the drain.
Check the non-return valve for proper positioning and proper direction.The Compressor will not Engage
If the machine is equipped with the refrigerant compressor protection system, refer to the Testing and Adjusting, UENR4125, "Compressor Protection System - Test" to test the refrigerant compressor on delay timer assembly.System Condition 13
Low-pressure gauge reading is above normal. For normal operating pressures, refer to Table 1.
High-pressure gauge reading is below normal. For normal operating pressures, refer to Table 1.Note: Ambient temperature is above 21°C (70°F).
Air flow to the operator compartment is warm.Probable Cause
The thermostatic switch is stuck open. This condition does not allow the magnetic clutch to cycle the compressor.
Check the wire connectors on the thermostatic switch and on the magnetic clutch.
The connection of wire leads on switch is improper. The connection of wire leads on the magnetic clutch is improper.
Check for insulation that is broken. The insulation failure can expose the wires from the switch to the magnetic clutch.
The wire that connects the switch to the magnetic clutch has an opening.
Check the resistance of the coil with a multimeter. Refer to the Testing and Adjusting, UENR4125, "Refrigerant Compressor - Test" section.
Check for the proper electrical ground at the magnetic clutch.
Touch the two wires on the switch together. Check for the proper operation of the magnetic clutch.
To check the electrical components, refer to Testing and Adjusting, UENR4125, "Machine Preparation For Testing and Adjusting".If the problem is a loose wire on the switch or a loose wire on the magnetic clutch, make the repairs that are needed. If the wires to the clutch are damaged, the damaged wires can cause the switch to remain open. Make the needed repairs to the damaged wires. To ensure the correct system operation, perform a performance check. Testing and Adjusting, UENR4125, "Air Conditioning Performance - Test".
The charge of refrigerant in the capillary tube has been lost.
If the capillary tube has no charge or the switch remains open, the problem is in the thermostatic switch.
Replace the switch.
To ensure the correct system operation, perform a performance check. Refer to Testing and Adjusting, UENR4125, "Air Conditioning Performance - Test".The Compressor Continues to Cycle or the Clutch will not Disengage.
Note: The cause of the problem may be one of the following conditions: low charge, overcharge, and evaporator freeze-up.System Condition 14
Low-pressure gauge reading is below normal. For normal operating pressures, refer to Table 1.
High-pressure gauge reading is below normal. For normal operating pressures, refer to Table 1.Note: Ambient temperature is above 21°C (70°F).
The air flow to the operator compartment is cold, or the air flow may be restricted completely at times.Probable Cause
The thermostat switch is held closed. There is a short in the wire to the magnetic clutch. The magnetic clutch will not release.
Check the wire that goes to the magnetic clutch. The wire may have an electrical short.
Replace the thermostat switch.
Make the necessary repairs to the magnetic clutch.Additional Refrigerant Circuit Problems for Orifice Tube System
System Condition