How Do I Free a Seized Automobile AC Compressor?

Automobile air conditioner (AC) compressors can seize and require troubleshooting to restore normal function.

An automobile air conditioner (AC) compressor compresses refrigerant and allows it to circulate through the system, cooling the vehicle. A seized AC compressor causes the AC to malfunction. Freeing a seized AC compressor involves determining what caused the seize and performing the necessary repairs.

Leaks

An AC compressor consists of a pump; a pump leaking fluid can seize. The driver can use a leak detector to determine the location of the leak and seal it accordingly. After the leak is sealed, compressor kits, available at many auto supply stores at a nominal cost, contain lubricating oil for an oil change and refrigerant to top off the compressor. Restoring proper oil and refrigerant levels in the compressor should free it and restore its normal function.

Wiring

An auto AC compressor receives electrical power via a wire that connects it to the electric clutch. A loose connection or short in the wire can cause the compressor to lose power and seize. Tightening the connection or replacing the faulty wire should correct the compressor seize.

Debris

Dirt, sediment and other debris trapped in the compressor pump and hoses can clog the compressor and lead to seizure. Disconnecting the hoses and pump and flushing them thoroughly before conducting an oil change and refrigeration refill should free up the AC compressor.

References

• AA1Car.com: Air Conditioner Compressor Failure
• "How to Repair Your Car"; Paul Brand; 2006

Resources

• "The Complete Idiot's Guide to Auto Repair"; Vyvyan Lynn and Tony Molla; 2007