AC Compressor

The AC compressor is one of the most important, if not the most important, components of a vehicle’s air conditioning system. It is responsible for pressurizing the AC system and keeping the refrigerant flowing so that it can function properly. Because it functions in a continuous cycle on and off, it is subject to wear every time the AC is turned on. Just like any other component on a vehicle, it will eventually fail and need to be replaced.

AC Compressor images

  • Leakage
  • Development of noise. A leaking or worn out bearing will produce a high pitched squealing or grinding sound
  • Insufficient or no cooling performance
  • Error code in the air-conditioning control unit or engine / central control unit
  • Cabin temperatures higher than normal – AC no longer blowing as cold as it once did.
  • Compressor clutch is not moving
  • Bearing damage caused by a defective tensioner or by wear
  • Leaks in the compressor shaft or the housing
  • Mechanical damage to the compressor housing
  • Contact (electrical connections)
  • Electrical control valve
  • Solids (e.g. swarf)
  • Humidity (corrosion etc.)
  • Defective tensioning elements and ancillary units
  • Lack of refrigerant oil
  • Lack of refrigerant
  • Too much refrigerant.
  • Inadequate oil lubricant – If there’s not enough, the system can’t work properly and all kinds of problems can result, including AC compressor failure.
  • Electrical problems
  • Testing this sensor’s intermittent failure can be difficult due to its ability to start working again. Though you can test the sensors resistance using a voltmeter the true way to test the sensor is to use an oscilloscope when the sensor is hot this is the only true way to test if the crankshaft sensor needs replacement.
  • Due to the complexity and nature of how compressors are assembled, it is usually easiest to replace the entire compressor instead of attempting a repair.
  • Compressor clutch is not moving – Sometimes the clutch itself can be replaced, but usually replacing the entire compressor turns out to be the most efficient repair.
  • Electrical problems – But electrical problems are often easily preventable when an experienced tech inspects your system: he can spot and repair damaged wiring, fuses and contractors before they take down your system and cause AC compressor failure.

References