The air conditioning system in your Jeep Liberty compresses a refrigerant and blows the resulting cold air into the passenger cabin. When this system is not working properly, it can be because the pressure in the AC lines is too low, or because the compressor has failed. Replacement compressors can be purchased from most auto parts stores. Recharging your air conditioning system can be done by most mechanics. However, before you replace anything, you should troubleshoot the problem so that you know what's wrong.
Open the fuse panel cover by pulling down on the cover with your fingers.
Pull the fuse for the air conditioning using the fuse pullers in the fuse panel. Use the fuse diagram on the underside of the fuse panel if you are having trouble locating the fuse for the air conditioning.
Check the metal strip in the fuse. If the fuse is blown, replace it with a new fuse of the same amperage.
Open the bonnet of your Jeep Liberty. Locate the low pressure air conditioning line. The air conditioning lines will be steel lines running on the left side of the engine bay. The low pressure line on your Liberty is marked with a blue valve cap on the line.
Unscrew the blue valve cap and screw on the air conditioning pressure gauge.
Turn the knob on the pressure gauge counterclockwise to allow pressure into the gauge.
Check the gauge reading. Your AC pressure gauge should be colour coded. If the needle on the pressure gauge sits within the green band, the pressure in the air conditioning system is fine. If it falls outside of this range, then you will need to have the AC system checked.
Check the belt that wraps around the pulley on the end of the Liberty's air conditioning compressor. The belt teeth should not be damaged in any way. If they are, replace the belt.
Start the Liberty's engine and turn on the air conditioner. If you do not get cold air blowing from the air conditioner within 15 minutes of starting the engine, the air conditioner compressor needs to be replaced.