no defroster blowing

Hello,

This could be due to a faulty mode door actuator. The mode door actuator is what controls the flow of the air. Faulty mode door actuator can cause the air to blow only out of one position and not the other.
On your vehicle there are two mode door actuators. One for the floor and other for the panel/defrost.
So, the issue could be the panel/defrost actuator. It is probably just stuck in panel mode.
The actuator is located behind the dash.

I have attached diagrams for your reference.

Please let me know if you have any questions.
Thank you.

https://www.2carpros.com/articles/air-vents-stay-in-the-defrost-position