An air conditioning compressor circulates refrigerant through your AC unit.It is possible that a faulty compressor is the cause of your AC not working.If you want to diagnose problems with your compressor, you can use a multimeter or a device.Once you figure out what the problem is, contact a heating and air specialist or an automotive mechanic.
Step 1: The power to your air conditioning unit should be turned off.
It is important that you do not shock yourself when you check the compressor.There is a power shut off switch on the wall next to the central air unit.Go to the off position and find the switch.The circuit breaker that controls the power to the area where the AC unit is should be found if there is no switch.To turn off the power, flip the circuit.If the AC is a window unit, you can shut it down.
Step 2: Remove the faceplates from your AC unit.
To see the internal components of the compressor, you have to remove the faceplates.There are holes and screws on one side of the unit.Place the screws in a safe place with aPhillips head screwdriver.The process can be repeated on the top of the unit.You should be able to see the inside of the unit once the screws are removed.
Step 3: If you have an electric access panel, you should remove it.
You have to remove another panel to reveal the wiring of the AC unit.You can loosen the screws on the access panel by using a screwdriver.The access panel can be used to reveal the unit's wiring.
Step 4: Look for damage to the compressor and wires.
The compressor will look like a tank.Make sure the wires are undamaged by inspecting the compressor.The wires that run from the compressor are the most likely cause of failure.Take notice of the compressor.You will most likely need to replace the compressor if there is visible damage.You should call a certified air and heating specialist if you need to repair your compressor wires.It will be cheaper to replace the compressor.
Step 5: The compressor has burnt or damaged terminals.
The side of the compressor has metal terminals that the wires connect to.There should be no burns or damage to the terminals.If there is no visible damage to the terminals or wires, you need to test them with a multimeter to make sure they can hold a current.
Step 6: The unit needs to cool down.
Touch the top of the unit with your hand.Your multimeter settings may be thrown off if the unit is still warm.Wait until the AC unit cools down.If there is no power running to the unit, you will shock yourself.
Step 7: Set a multimeter to continuity.
The front of your multimeter should have a dial on it.If you set the dial to continuity, you will be able to determine where the fault is.There is an electrical flow between the terminals.The terminal is likely to be broken or damaged if there is no flow.
Step 8: The terminals marked are C, R, and S.
The access panel should have three terminals on it.Common, run, and start are what these letters stand for.
Step 9: The red and black pins should be placed on C and S.
The pins should be placed on the black and red wire.The multimeter should have a reading of less than 30 if you place the pins on the terminals.This reading indicates that your compressor may be broken.
Step 10: The red and black pins should be placed on C and R, respectively.
This time, check the continuity between the common and run terminals.The continuity should be read under 30.
Step 11: The red and black pins are on R and S, respectively.
The continuity between the run and start terminals should be under 30.
Step 12: If your readings are high, you should buy a new compressor motor.
If your readings are over 30 you will need to replace your compressor motor.The broken compressor motor can be repaired by a heating and air specialist.
Step 13: If your readings are low, you should buy a new compressor.
It means that the connection between your terminals is faulty and you will need to get a replacement compressor.Refer to a heating or air specialist for a second opinion if you want to make sure that this is the case.
Step 14: You should turn off your vehicle.
The moving parts under the hood should be turned off.Before you check your compressor, make sure your engine and internal parts are cooling down.
Step 15: Find your AC compressor clutch by opening the hood of your car.
The compressor clutch is located on the left side of the car.It will look like a piece of metal with wires and tubes.
Step 16: The compressor should be looked at for damage.
Older vehicles are prone to rust.Check the compressor for damage.You should check the wires and tubing to make sure they aren't damaged.If they are, you can replace them cheaper than buying a new compressor.
Step 17: The wires from the battery to the compressor need to be disconnected.
The side of the compressor should have wires running from it.The ground wire is the one that carries the electric current.Pull the wires to remove them if you press on the sides of the plastic fittings.You will use this to test the compressor.
Step 18: To get a reading, insert the multimeter pins into the plastic fitting.
Put the pins on the contacts when you set your multimeter to continuity.If current is running through your compressor clutch, you should set the dial on your multimeter to continuity.
Step 19: The coil should be replaced if the reading is above 5 ohms.
It means that your wires are bad and you will have to replace them.If your reading is over 5 ohms, it's most likely that you have a bad coil, and you'll need to have it checked by a mechanic.
Step 20: The AC compressor clutch needs to be connected to a battery.
The negative or black battery cable needs to be connected to the compressor.Attach the black wire to the negative side of the battery.The red wire should be connected to the positive side of the battery.Touch the metal end of the wire.The clutch should be engaged back and forth.If the clutch does not move or make a noise, that means there is an issue with the contacts.