Poor performance could be due to one or more factors:
Low refrigerant: - An air conditioning system
requires a minimum amount of refrigerant to cool properly. If the
refrigerant level is low, it will work less efficiently and will not
Dirty condenser: - The condenser is the heat
exchanger which cools the hot high pressure refrigerant after it exits
the compressor so that it can condense into a liquid. If the condenser
is full of leaves, insects or other road debris, air flow through the
unit may be impeded to the point where little cooling can take place.
Cleaning the condenser should cure this problem.
Condenser cooling fan not working: - The condenser
often has its own separate electric cooling fan. This fan should come
on, and remain on, when the air conditioning system is operating. If
the wiring, fan motor, or motor relay is defective, the fan may not
Internal blockages: - Any type of debris, e.g.
rust, in the system may block the tube or the metering valve through
which refrigerant flows into the evaporator. This will cause a loss of
cooling, and potentially cause damage to the compressor as the system
probably relies on oil circulating with the refrigerant for
Air or moisture contamination: - The refrigerant
inside the system, which must remain free of moisture, can freeze and
form ice that will cause blockages. Contamination can result from leaks
in the system or failure to vacuum purge the system prior to recharging
it with refrigerant.
Other electrical or mechanical problems: - These
would include compressor wear, the compressor clutch failing to engage,
metering valve failures, inoperative pressure switches, etc. Precise
diagnosis will require a technician who has all the necessary tools and
equipment, and who has been trained in this highly specialised