On-Vehicle Inspection

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.

Set on manifold gauge set . See MANIFOLD GAUGE SET .
Start engine .
Inspect compressor for metallic sound :
Check if there is a metallic sound from the compressor when the A/C switch is on.

If metallic sound is not heard, replace the compressor assembly.
Inspect refrigerant pressure . See ON-VEHICLE INSPECTION .
Stop engine .
Inspect visually for leakage of refrigerant from safety seal .
Using a gas leak detector, check for leakage of refrigerant. If there is any leakage, replace the compressor assembly.
Set off manifold gauge set . See MANIFOLD GAUGE SET .
Check for leakage of grease from clutch bearing .
Check for signs of oil on pressure plate .
If necessary, repair or replace.
Inspect magnetic clutch bearing for noise :
1. Start engine.
2. Check for abnormal noise from near the compressor when the A/C switch is OFF.
  If abnormal noise is being emitted, replace the magnetic clutch.
Inspect magnetic clutch operation :
1. Disconnect the connector.
2. Connect the positive (+) lead from the battery to terminal 3 and the negative (-) lead to the body ground. See Fig 1.
3. Check that the magnetic clutch is energized.
If operation is not as specified, replace the magnetic clutch.

Fig 1: Locating Terminal No. 3
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Inspect compressor lock sensor resistance :
1. Disconnect the connector.
2. Measure resistance between terminals 1 and 2. See Fig 2.
  Standard resistance:
  
  165 - 205 +/- at 20°C (68°F)
  
  If resistance is not as specified, replace the compressor.
Fig 2: Locating Terminals No. 1 & 2
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002