why there is a lot of cool air flowing from the right rear end duct?

Anytime we have incorrect air temperature from any of the ducts we need to start with checking the system pressure.

Basically, when the system gets weak it is not able to completely cool the air.

So, we need to start with this, and we can go from there.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Once we know what the pressure is we can make the next decision on where to go.

Below you will see the chart we need to follow on what we find with the temps.

So please hook up a gauge set and let me know what you find, and we can go from there.

Thanks

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