Cabin air filter
If your vehicle has a cabin air filter, check it at least once a year to make sure it’s not clogged.
A clogged cabin air filter can reduce airflow across the air conditioning evaporator coil to the point where the evaporator freezes over. The evaporator temperature sensor should kick in to shut off the flow of refrigerant, but the icing may have already started. That would cause a cool/no cool condition. A clogged filter not only reduces cooling, but causes the air conditioning system to work harder which lowers your gas mileage. In addition, a clogged filter causes the blower motor to work harder and draw more current. That causes the motor to overheat and can cause premature failure of the speed regulating blower motor resistor or power transistor. Cabin air filters are an important component and should not be ignored.
Consult your owner’s manual for the procedure to inspect and replace your cabin air filter, or click on this link to find the instructions for your vehicle
© 2014 Rick Muscoplat