• Low refrigerant. If your A/C system has lost 10-15% or more refrigerant it looses efficiency and can't get as cold.

• Overcharged A/C system. Someone adds to much refrigerant and the A/C system looses efficiency and can't get as cold.
• Dirty condenser. Mounted in front of the it cools the refrigerant so it can condense back to a liquid state. If the condenser is plugged by leaves, bugs and dirt it can't cool as well. Cleaning the condenser should fix the problem.
• Inoperative cooling fan. The vehicle could also be running hot or overheating depending on fan configuration. Variable speed computer controlled fans might be on but spinning to slow.
• Air or moisture. If the A/C system is contaminated with air it reduces the cooling efficiency of the system. Moisture can freeze and form ice that cause blockages in orifice tubes and metering valves. Air and moisture can enter a system through un-repaired leaks, adding refrigerant without purging air from lines and charging an empty system without pulling a vacuum first.
• Blockages. If the orifice tube, metering valve, accumulator or dryer become restricted it will cause a loss of cooling. A/C systems get restrictions from worn parts (compressor and hose deterioration) or desiccant contamination from the dryer or accumulator.
• Worn compressor or clutch & coil. Compressors wear out internally and loose efficiency. A clutch assembly can wear out and slip or intermittently disengage causing the compressor to quit pumping.
• Electrical problems. Switches, wiring or computer problems that cause the compressor, cooling fan or blower motor to quit working.
• Engine problems. A check engine light that is on will sometimes cause the engine computer to disable the A/C. Engine problem has to be repaired.
• Climate control problems. Climate control system not working properly will cause to much or not enough cold air into vehicle.