air blowing from vents

[Ernie]

It seems like have insufficient air blowing from my vents on my car when I have the heat on. If I have it set to the cool or cold setting there seems to be more air blowing from the vents. Any idea what would cause this and how I can correct it ?

Topic

[Sam]

I would bet the heater core is externally plugged up, I would take out the cabin filter (if it has it) and inspect for holes or anything letting large amounts of debris through.

[Ernie]

There’s no cabin air filter on the car, I checked the blower motor and it’s clean there’s no leaves, or derbies in that area. Any other ideas on what to check?

[Sam]

The air flow will generally be a bit lower on heat, but if it’s noticeably lower then you most likely have something not letting air through the core.

[EricTheCarGuy]

Air flows through the evaporator before the heater core. Perhaps there’s an issue with blockage as suggested but there could also be an issue with the blend door that directs air between the 2 components. You may end up having to get into the HVAC to find the issue. You may be able to access the blend door controls from under the dash, consult the manual for your vehicle.

[Author]

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