A/C airflow reduces overtime?

JROBBB

MEMBER
2010 HYUNDAI TUCSON
2.0L
4 CYL
4WD
AUTOMATIC
160,000 MILES

After about 20 minutes of running the A/C, the air coming out the vents is slowly reduced until airflow is very limited, but it's still cold. If I turn the A/C off, the airflow comes back fairly quickly. The longer I leave it off, the longer it will work for. I've added refrigerant and the pressure is correct and not dropping. Could this be the evaporator coil freezing and melting? Any cheap fixes? Thanks!

3 Replies

JACOBANDNICKOLAS

MECHANIC
108,117 POSTS

Hi,

Have you checked the cabin air filter? If it hasn't been changed, it could be plugging.

The cabin air filter is located behind the glove box and is very easy to check and replace.

Here is a link that shows in general how to replace one:

https://www.2carpros.com/articles/how-to-change-an-air-cabin-filter

If you look below, I attached the directions specific to your vehicle. If you haven't replaced this, check it and let me know what you find.

Take care,

Joe

See pics below.

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Saturday, August 6th, 2022 AT 10:28 PM

JROBBB

MEMBER
2 POSTS

Thanks, Joe. Yes, it's a new filter. The key here is that it blows hard for like 30mins, then decreases, but if I turn the AC off, it blows hard again shortly after. That's why freezing made sense to me, but I'm not sure if it would be the evaporator coil or something else.

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Sunday, August 7th, 2022 AT 1:07 PM

JACOBANDNICKOLAS

MECHANIC
108,117 POSTS

Hi,

That is very possible. There is an evaporator temperature sensor that is designed to signal the compressor to shut down to prevent freezing.

If you look at pic 1 below, it shows the location of the sensor. Pics 2, 3, and 4 explain how to test it.

If you find it is bad, the remaining pics are the directions for the removal and replacement of the sensor.

Let me know what you find and if this helps.

Take care,

Joe

See pics below.

Images (Click to make bigger)