Rear Cooling Unit: Inspection

WARNING: This page is about a different car, the 2003 Lexus LX 470. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT BLOWER MOTOR OPERATION
Connect battery positive (+) lead to terminal 1 and battery negative (-) lead to terminal 2, then check that the motor rotates smoothly.

If the motor rotates smoothly, check the wire harness, otherwise, replace the blower motor.

Fig 1: Inspecting Blower Motor Operation
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT THERMISTOR RESISTANCE
1. Place the thermistor in cold water. Measure resistance of the thermistor as the water temperature increases.
  
  Fig 2: Inspecting Thermistor Resistance
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Compare the readings with the chart.
  If the values meet the specifications, check the wire harness. Otherwise, replace the thermistor.
  
  Fig 3: Thermistor Specification Chart
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT MAGNETIC VALVE OPERATION
Check the air passage through the valve, with and without the battery positive voltage applied, between terminals as shown in the chart.

Fig 4: Magnetic Valve Operation Chart
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Otherwise, replace the magnetic valve with the expansion valve.

If operation is as specified, check the wire harness.

Fig 5: Identifying Magnetic Valve Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT EVAPORATOR
1. Check the evaporator fins for blockage.
  If the fins are clogged, remove them with compressed air.
  
  NOTE: Never use water to clean the evaporator.
2. Check the fitting for cracks or scratches.
  If necessary, repair or replace.