Start the excavator. Engage the A/C system with the blower fan on high. Run the excavator at full RPM for approximately 15 minutes, with the cab door closed.
Check the temperature at the louvers (Item 1) [Figure 70-30-1] with a thermometer [Figure 70-30-2].
The louver temperature should be between 2,2 – 11,6°C (36 – 53°F). depending on the amount of humidity in the air.
If louver temperature is too high see the System Troubleshooting Chart. (See Gauge Pressure Related Troubleshooting on Page 70-30-2.)
Check the blower fan for proper operation, and replace if necessary. (See Removal And Installation on Page 70-130-1.)
Check the air conditioning compressor belt for wear or damage. (See Fan Belt Replacement on Page 70-20-3.)
Check the A/C evaporator coil for dirt or mud, and clean if necessary. (See Evaporator / Heater Coil on Page 70-20-6.)
Inspect the sight glass located on the receiver / drier for air bubbles. (See Gauge Pressure Related Troubleshooting on Page 70-30-2.)
Check the engine coolant to see if it is bypassing the heater valve.