Cool air comes out of the vents on the passenger side of car, but not the driver’s side. To try and get a little cool air from the vents on the driver’s side, I have to turn the fan speed down to medium or below medium. Even then it’s not truly as cool as the passenger side.
Failed AC blend door actuator. Cheap part, might be easy to change, might be a hard, depending on which actuator failed. Common problem.
When the system is low on refrigerant sometimes one side will be warm and the other cool. Have the A/C system check out.
I’m guessing this Cadillac has 2-zone automatic climate control
If so, it might very well be a blend door actuator, as mentioned above
But a low refrigerant charge can also cause symptoms like this, as also mentioned above