Rear Cooling Unit: Inspection

WARNING: This page is about a different car, the 2004 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 Resistance/Temperature Graph
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.

MAGNETIC VALVE CONNECTOR TERMINAL CONNECTION CONDITION

Condition	Air passage
Apply B+ between terminals	Free passage
Not apply B+ between terminals	No passage

Fig 4: Identifying Magnetic Valve Connector Terminals

Otherwise, replace the magnetic valve with the expansion valve.

If operation is as specified, check the wire harness.

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.