So Fix it

If the air-conditioning compressor on a late model car does not engage, the system is probably low on rigerant and the low-pressure switch prevents the compressor from turning on. This problem goes away by simply adding rigerant. Opening a can of R134a into the system usually overrides the low-pressure switch and allows the air-conditioning compressor to engage normally. On older cars, the air-conditioning compressor has to be engaged manually to recharge the system. The procedure is simple and usually takes less than a minute.

Instructions

1

Check the compressor oil level. Add more oil if necessary. Since different manufacturers have different procedures for checking compressor oil levels and filling compressors with oil, er to the auto manufacturers shop manual for specific instructions.

2

Locate the single wire connector near the front of the compressor and unplug it.

3

Hook one end of the fused jumper wire to the compressor side of the wire connector.

4

Hook the other end of the jumper wire to the positive terminal of the battery. By supplying voltage to the compressor, the compressor will engage manually without even turning on the air-conditioning switch inside the car.

The circuit of refrigerant flowing through a vehicle is made possible largely because of the hard work of the air conditioning (AC) compressor. It not only pumps refrigerant throughout a vehicles AC system but pressurizes it as well. Having information on diagnosing compressor issues can be beneficial to vehicle owners.

Lubricant Diagnosis

An auto AC compressor consists of moving parts which need adequate lubrication to function properly. Leaks allow lubricants to escape which, in turn, is dangerous for the life of the compressor. Electric leak detectors are available and can assist with locating these leaks.

Pressure Diagnosis

An AC gauge can be used to determine if a compressor is building up enough pressure to function properly. Several things can cause a compressor to lack sufficient pressure, such as worn out piston rings. Worn out engine cylinders are known to cause this type of problem as well.

Clutch Diagnosis

Problems with the clutch will keep a compressor from turning. The clutch can be tested using a jumper wire to jump the clutch lead to see if the clutch reacts. Blown fuses and faulty wiring are known to cause issues with a compressors clutch.