Hello,
If you have air flow issues from one of the vents, it could be due to a faulty air door actuator. It is possible for the mode door actuator not to be engaged all the way and restrict air flow.
Another possibility is having a blockage or misaligned air duct.
In order to find out what the exact cause is, you will have to access the restricted air duct and see if everything is aligned properly.
Also, the issue is only with air flow or air temperature as well.
It might be a good idea to check the air temperature on each vent to verify proper flow.
Since the Prado is not sold in the United States, I am unable to provide you with diagrams.
Please let me know if you have any questions.
Thank you.
https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position
Monday, January 17th, 2022 AT 1:18 PM