A/C airflow reduces overtime?

Tiny
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!
Saturday, August 6th, 2022 AT 7:47 PM

3 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,108 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

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Saturday, August 6th, 2022 AT 10:28 PM
Tiny
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
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,108 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

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Sunday, August 7th, 2022 AT 10:14 PM

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