We are a team of ASE certified mechanics that have created this guide to help
you save money while doing the job yourself, or at least see what you are paying
for when having the job done at a shop. The HVAC system is designed to blow air
from either the floor, mid or defrost vents. In the following guide we will show
you what to check for depending on the symptoms of the problem which is based on
what you can hear, and feel.
Let's Jump In!
When the HVAC system is on you should be able to hear the blower motor running,
this sound should change pitch when adjusting the fan speed. If no sound is
heard this means the blower motor is not working, start by testing the
relay, resistor or
blower motor itself.
If exact blower motor, fuse or relay locations are needed you can
ask our experts to supply you with the information
needed (free), or consult an online resource such as AllData DIY (pay).
If you can hear the blower fan working but still feel nothing from the vents,
or the vents are in the incorrect position this means the
mode blend door actuator is
not working correctly. This can sometimes be accompanied by a ticking noise
which is telling you the gears inside the actuator have failed. The actuator
can be found by flowing the noise, if no noise is heard the location is needed,
again you can ask one of our experts for help.
Some vehicles are equipped with a cabin air filter or Hepa filter which
is designed to clean the air in the HVAC system prior to exiting the vents.
When this filter clogs it hinders or stops the air flow supplied to the vents,
to check the cabin filter's condition locate the HVAC housing which can be either
beneath the dash or under the hood near the base of the windshield on the passenger
remove the cabin air filter to inspect and replace as needed. To find out
if your vehicle has one of these filters consult your owners manual or
ask one of our experts to help.
If just one vent is having problems check the flow control door that is
located at the vent outlet which is controlled by a thumb wheel that when activated,
will open and close the vent air flow door. Work the thumb wheel from side to
side while checking the airflow which should stop and start again. Sometimes
these doors can get stuck or broken which will block the air flow, in this case
the vent will need to be replaced.
There are two air intakes for the HVAC system, one is fresh air which is
drawn in at the base of the windshield, the other is recirculated air which
re-takes the air from inside the vehicle. If one of these intakes becomes clogged
by a piece of paper, plastic bag or cloth or other form of blockage the air
flow will stop. Locate the intakes and inspect for such items located at the
base of the windshield (external), and at the passenger side footwell (internal).
Our certified technicians are ready to answer air vent
questions for free. We hope you saved money and learned from this guide. We
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